Applying Grime's Triangle to my Garden

One of the problems horticulturists have is the struggle of knowing how to appropriately site and manage plants in naturalistic plantings.

One of the most powerful tools I use to help with these issues is Grime’s Triangle or the CSR theory—a framework that categorizes plants based on their competitive (C), stress-tolerant (S), or ruderal (R) strategies.

Imagine being able to look at a plant, notice a few characteristics, and immediately know how to use it. That’s the power of understanding plant strategies. For me, these strategies are more useful than simply labeling plants as annual, perennial, or biennial because they reveal more about how the plant behaves in various conditions.`

But, theory only takes you so far. So, I wanted to share with you readers five ways I apply the CSR theory at Ephemera Farm.

1. Covering the Ground with Ruderals

Ruderals are fast-growing plants that thrive in disturbed areas. I use species like Lupinus subcarnosus (sandyland bluebonnets), Nemophila phacelioides (baby blue eyes), and Streptanthus maculatus (clasping jewelflower) to cover open gaps in my garden beds in spring while I wait for plants to emerge. Later in the summer, I count on Gomphrena globosa (globe amaranth), Celosia spicata (celosia), Bidens aristosa (tickseed sunflower), and annual sunflowers to provide summer interest and occupy unplanted spaces.

Ruderals in the form of cover crops can also improve the soil and prevent weeds, especially in areas where I grow edibles and cut flowers. In late summer I will sow crimson clover and mustard greens under my blackberries. These helps to prevent weed growth overwinter.

Lupinus subcarnosus (sandyland bluebonnet) fills in gaps in the garden through winter and early spring while other plants are just starting to grow.

Later in the summer, I use ruderals to cover spots I haven’t planted yet. The plus is that many of them also serve as cut flowers.

2. Choking Out Weeds with Competitors

In the more productive parts of my property where water, light, and nutrients are abundant, weeds can take over if the ground isn’t covered. In these areas I use competitors to help reduce weed growth. I interplant Carex cherokeensis with Symphyotrichum praealtum (willow aster) and Helianthus angustifolius (swamp sunflower). Carex covers the ground early in the spring, while the aggressive growth of the aster and sunflower chokes out weeds later in the season. This dynamic pairing ensures the area needs minimal attention during the year.

The dense growth of Helianthus angustifolius (swamp sunflower) limits the growth of weeds and unwanted species in the more fertile parts of our property.

3. Stress-tolerators add diversity to lawns

Stress-tolerators are plants that survive in tough conditions. Some of them go dormant for parts of the growing season, and we can use them to add diversity to our gardens and lawns.

Many people plant Narcissus (daffodils) for bright spring color. However, the downside is the abundant foliage that remains for months after flowering, which is necessary for next year’s blooms. The bulb foliage is also an issue in lawns.

I prefer stress-tolerators in turf that sync up with the mowing season like Claytonia virginica (spring beauty). This charming little plant blooms from December to March before going dormant. Later in the fall, Lycoris radiata (red spider lily), Rhodophiala bifida (oxblood lily), Habranthus tubispathus var. texensis (copper lily), and Zephyranthes chlorosolen (evening rain lily) bloom with their foliage emerging later and remaining up after frost. The last two have the added benefit of going to seed within a few weeks in case you need to do a few last cuts to the yard.

Zephyranthes chlorosolen (evening rain lily) blooms after a good rain. I’ll wait to mow over them until they set seed about three weeks later.

4. Disturbance for Managing Unwanted Plants

Disturbance is key to controlling unwanted plants and keeping competitors in check. In my garden, I use flame weeding and shallow cultivation to manage areas where weeds can take over. I’ve also invested in a Dutch hoe praised by Roy Diblik, which allows for easy push-pull weeding in tight planting spaces.

Tools like the wire weeder help me keep the soil disturbed to reduce weed growth.

5. Cutting Back Competitors

Many people have heard of the Chelsea Chop that helps to reduce upright growth. It is a form of disturbance that keeps competitive plants in check. It reduces their height, delays flowering, and makes blooms smaller but increases their number. While it is typically done in late May further north, I may cut plants back once or twice throughout the growing season.

I cut back a number of species here at Ephemera Farm to prevent them from flopping over—Eutrochium fistulosum (hollow joe pye weed), Vernonia baldwinii (western ironweed), Symphyotrichum (asters), Panicum virgatum (), Helianthus angustifolius (), and other giants. Most cut backs happen

Many of our the aster species I use from more northern haunts also have the issue that they emerge early enough in the spring that flowering is triggered under the short days. Cutting them back resets their flowering.

Cutting back competitors also helps reduce the ‘naked knees’ effect, where the lower foliage withers away and leaves bare stems.. A late spring or early summer cut back helps make clumps look tidier throughout the whole plant.

Symphyotrichum drummondii (Drummond’s aster) stems are already elongating in early April, and left unchecked will result in wiry stems come September.

Cutting Symphyotrichum drummondii to the ground helps reset the plant growth and results in a more densely flowering perennial.

The off white flowers of Symphyotrichum drummondii appear in a mound from a plant cut back the previous spring.

By applying Grime’s Triangle to my plantings, I create dynamic, resilient garden spaces that evolve with the seasons and thrive in various conditions. Understanding plant strategies helps me place the right plants in the right spots, which ultimately leads to healthier, more sustainable plantings.

Now, it’s your turn. Whether you’re filling gaps in your garden with fast-growing ruderals, using competitors to outcompete weeds, or diversifying your plantings with stress-tolerators, the principles behind Grime’s Triangle can guide you to make smarter planting choices. By observing your plants’ behaviors and using their strategies to your advantage, you can create a garden that not only looks beautiful but thrives with less maintenance and more resilience. Start small, test a few strategies, and watch how your garden transforms with the power of plant strategies in action.

Want to learn more? My presentation The Plant Strategies Playbook (⬆️) delves further into Grime's Triangle—an approach combining site, species, and management into one powerful framework. If you're eager to make smarter planting choices, fill gaps in your garden, and predict how plants will grow, this session is for you. Save time, resources, and become the eco-friendly gardener you aspire to be!

Reflections from Spring

Grades are entered, and the school year is over for me.  

Whew.  

I’ve been in reflection mode lately as it feels for the first time in 10 months that I’ve had a chance to breathe.

Sure, teaching, running a student botanic garden, giving presentations across the country, hosting a podcast, and then writing a weekly newsletter is a full life, but after throwing a first child into the mix last July, well, suddenly priorities drastically shift.  Being inside listening to baby belly laughs beats pulling weeds.  

But, I’ve barely planted the vegetable garden for the summer, weeds abound, and there are spots I have yet to mow out back.  

It’s not all on me.  The soil has been so wet, wetter than the last few years, that recent time outside is often spent watching the rain.  This spring is one of those similar to when we first moved in where water would run through the property almost to June, and I would discover all the places I could get my mower stuck.  It makes it harder to tend the ground, but I know we’ll be wanting the moisture come August. 

The light beds in their spring glory

However, even though I’m behind on other areas of the garden, the light beds near the house have looked smashing this spring, to the point where I’ve gone from imposter syndrome with this whole naturalistic planting thing to thinking I’m onto something. 

We’ve lived at Ephemera Farm for 7 years, going on 8 in August. And, in this time I’ve watched this space evolve.  The beds, named for the way that light interacts with the plants throughout the day, started as trial spots where I threw plants into the ground after I cleared out the crape myrtles and turf near the garage.  Deer were wary to come this close to the house, and the higher ground didn’t flood and quickly drained after a rainstorm.  I watched what lived and died and replicated what was successful.  

A pathway leads through a verdant planting at Ephemera Farm.

At first these beds were disparate with different species in each one of them so that the plantings in one didn’t feel connected with the other.  Paths that I made felt more like borders separating space instead of a way through the planting.  

So, I started replicating species on both sides of the paths and scattered them throughout the beds to create a sense of community.  To further create harmony, I chose species that offered a cool color scheme featuring pink, blue, and purple with neutral white and pops of red and coral. I then added other beds on the west side of the drive near the orchard to make it have more continuity for the long view.  

Cool colors abound in the light beds in the spring.

Amsonia hubrichtii (Arkansas bluestar) offers a lovely pastel blue color in the garden.

The light beds continue into the orchard to give a greater sense of depth of the landscape.

I look at the light beds and sometimes think that it’s all too much.  I’ve made hard calls to simplify the plantings.  I’ve removed Liatris microcephala (Appalachian blazing star) that seems to struggle in our wet soils and edited out the Liatris pycnostachya (prairie blazing star) that fall over.  And, I dug out the Gladiolus communis ssp. byzantinus (Byzantine gladiolus) that were too much intense color for the area.  I’m left wondering should I remove more?

Is it all too much?

Sometimes editing happens on the fly. A lone Hymenopappus artemisiifolius (old plainsman, left of center) that had seeded itself into these beds didn’t seem right for this planting so out it went.

There, that’s better.

But, I have to remember my garden is also a repository.  There are plants like Penstemon murrayanus (scarlet penstemon). The original population of plants is gone, bulldozed two years ago and the site never built upon.  Where my Baptisia alba (white wild indigo) originated there’s now two driveways through that spot.

I mean, who could bulldoze this incredible native, Penstemon murrayanus?!?

Penstemon murranyanus in the orchard

Baptisia alba is an incredible primary plant to have bloom in the spring.

There are still things I need to fix.  Phlox pilosa (downy phlox) is beginning to get away from me some, but reducing its sprawl is an autumn and winter task I can tackle later.  In the orchard last year, I planted a mix of Penstemon laxiflorus (nodding penstemon) and Oenothera (Gaura) lindheimeri ‘Sparkle White’ (gaura).  I anticipated the gaura flowering later, but they flowered at the same time, and it was too much and too blended together.  I’ve made notes to separate them next year, and space them out more.  

Maybe there’s too much phlox?

Pink froth in the orchard from Penstemon laxiflorus and Oenothera lindheimeri ‘Sparkle White’. Which is which? Hard to tell but an easy fix this winter.

The one thing I feel like the beds are still lacking is a solid ground cover layer.  Carex texensis (Texas sedge) is doing well, but this time of the year it can start looking gangly with the long scapes after setting seed.  I cut them back to start with a fresh clump.  Muhlenbergia reverchonii (rose muhly) is quickly becoming a favorite.  After a couple of years in the ground it has already become a robust grass in the spring.  The height is not too bad for later in the year.  And, Sporobolus heterolepis (prairie dropseed) is doing well where the clumps have had time to mature.  But, many plants and divisions are still quite young.  I sow seed when I can, but patience must be had with that plant.  

I’ll add that my thoughts on relying solely on plants to cover the ground have also changed.  After a years long battle with trying to get gripeweed (Phyllanthus urinaria) under control, I’m finally having success with bark mulch to prevent germination.  It’s amazing how the little seeds seem to get into everything, even the crowns of plants. So, it’s a bit of a hybrid approach. Cover as much of the ground with plants as possible, but sprinkle in some mulch to cover the bare spots.

A part of the light beds where the groundcover layer has filled in well.

Carex texensis at the front of this image can get a bit wild looking toward the end of April.

I’m not done replicating what works. My next big task is to take divisions of the most impactful and ecologically beneficial plants and incorporate them into the front fences of the patch to have harmony with the current plantings. I’m going for the reclaimed fencerow aesthetic.

The patch fence seen behind the chairs is the next project here at Ephemera Farm. The goal is to use species in the light beds to create cohesion for the areas.

Now that we are in May, I’m not the only one taking a breather. The light beds have slowed down, too.  Most of the photos above are from mid-to-late April. The spring rush of color is over, and in early May there is a break before the riot of Echinacea and Pycnanthemum begin. The garden’s pause is a reminder that balance is essential. Just as the light beds take a break, I, too, find solace in this slower time.

The Plants of Oudolf Field

A couple weeks ago I wrote about our morning visiting to Oudolf Field last summer on our trip to the UK. I felt the content too long to try to cover it all in one piece, so I decided to focus on overall design approaches for the first part and the plants for the second part. To walk through an Oudolf planting is a masterclass in planting design. To see the knowledge and experience that a man has observed and witnessed over a lifetime of working with plants made real in front of you creates for breathtaking scenes and pairing. What delights me is how simple some of them were, even if it was a bright morning with strong light that intensified the colors and made the shadows harsh.

Exploring Oudolf Field I was armed with a nice guide that I bought in the gift shop that showed a fold out of the design along with plants that were included in each section. I’ve used that to help me key out some of the plants included below. Feel free to let me know if you see any errata.

An analogous color scheme featuring reds, pinks, blues, and purples. A few of the stars include Helenium ‘Moerheim Beauty’ (sneezeweed), Veronicastrum virginicum ‘Erica’ (Culver’s root), Echinops bannaticus (globe thistle), Thalictrum delavayi (Chinese meadow-rue), and Eupatorium maculatum ‘Atropurpureum’ (spotted Joe Pye weed).

Near the entrance to Oudolf field were plants primarily in blocks where they could play off each other. For example, here the soft yellow of Nepeta govaniana (catmint) contrasts well with Echinops bannaticus (globe thistle).

Here you can see the repetition of white spikes of Lysimachia ephemerum (willow-leaved loosestrife) and Veronicastrum virginicum. Such repetition helps make a planting feel more cohesive.

And, just in case you couldn’t see how amazing Culver’s root is from the above image, here’s another featuring ‘Diane’. Wowzers! I don’t think I’ve ever seen Veronicastrum virginicum look this good in the US.

The silvery-blue satellite dishes of Eryngium alpinum (alpine sea holly) really pop against the chartreuse Sesleria autumnalis (autumn moor grass).

Phlomis russeliana (turkish sage) always has such good texture in the garden with the large leaves and butter-colored verticillasters, and its audacity here is softened by the slender Panicum virgatum ‘Shenandoah’ (switchgrass) and Persicaria amplexicaulis ‘Firedance’ (red bistort).

I loved the unruly looking Datisca cannabina (false hemp) next to the neat sombreros of Helenium ‘Moerheim Beauty’.

Piet Oudolf says that brown is a color, too, and that’s certainly true of these brown seedheads from Monarda bradburiana (Bradbury’s beebalm). I’m not sure how I feel about their early demise. It feels too soon with the riot of color around.

And, some of the pairings were so simple and easy. Take how the purple highlights in this clump of Pancium virgatum ‘Shenandoah’ (which I’ll add here looks a bit more purple than the maroon I’m used to) plays off the burgeoning spikes of Liatris spicata (dense blazing star).

In the middle of the field was the Sporobolus heterolepis meadow where many species erupted from the prairie dropseed haze, and with a good breeze it was fun to watch Dianthus carthusianorum (Carthusian pink) and Echinacea pallida (pale coneflower) straight species and ‘Hula Dancer’ dance in the wind.

I liked how the silvery Amorpha canescens (lead plant) amorphously blended into the silvery seedheads of prairie dropseed.

One of my absolute favorite combinations of the day featured the differing textures yet echoed colors of Sedum ‘Matrona’ (stonecrop), Allium christophii (Persian onion), and Sporobolus heterolepis.

Towards the back of the field, the plantings shifted more back into block style planting. From this angle, you can see a wonderful combination of purple plants featuring Symphyotrichum lateriflorum var. horizontale (horizontal calico aster), Stachys officinalis ‘Hummelo’ (betony), and Panicum virgatum ‘Shenandoah’. The glaucous Eryngium yuccifolium (rattlesnake master) punctuates the planting.

In some parts Nassella tenuissima (Mexican feather grass) was woven through the planting, and with the wind it added such movement to the planting.

It amazes me just how black Symphyotrichum lateriflorum var. horizontale gets in the UK, and really it is just that the plant is further north. For us, these asters tend to be green with a smudge of charcoal. And, how good is the aster paired with the dark inflorescences of Molinia caerulea 'Edith Dudszus' (purple moor grass) in the foreground!

Designers talk about transparent perennials, and I so wish that I could add Sanguisorba officinalis ‘Blackthorn’ (burnet) to my planting palette here in the south. It’s like looking at giant pink cupcake sprinkles—I just want to eat it up!

Karen stands for a sense of scale of the billowy Amsonia hubrichtii (Arkansas bluestar). Even in the UK, these bluestars can get huge!

A nice patch of the bronzed Aruncus ‘Horatio’ (hybrid goat’s beard) stands between a mammoth clump of Eupatorium maculatum ‘Atropurpureum’ and an elongating Symphyotrichum novae-angliae ‘Violetta’.

And, we saw many pollinators in the planting. I was delighted to watch this bee dot around on our native friend Asclepias incarnata (swamp milkweed), and when I got the photos on my computer, I was even more thrilled to see that I had captured some orange milkweed pollinia stuck to its feet!

Phlox drummondii and a Texas (Mini) Superbloom

I love ruderals for their flashy essence. They are the YOLO of the plant world. Live it up because life is short.

And, in the youth of a planting, ruderals are wonderful for quickly filling the gaps, providing color, and helping support ecology. Often, perennials need a few years to get established before they can have a presence, but ruderals hit the ground running, often blooming within months of their seeding while covering the ground to reduce weed growth.

I have been noting good choices for east Texas and the deep south. A new one I can add to my growing list is Phlox drummondii (annual phlox). I’ve seen it scattered pretty sparsely on roadsides, but thanks to a planting project just north of Nacogdoches, TX where it is intensely planted, I have a new appreciation for this native (header image). Over the past month I’ve watched this roadside planting explode with a multitude of tints and shades of red as I drive into town.

What a wonderful explosion of color! I don’t know if I’ve ever seen so much color diversity in species mix as I did with these Phlox drummondii.

If you’re unfamiliar with Phlox drummondii, annual phlox is a short lived native wildflower with sticky leaves. It is native to Texas and Oklahoma, though in some states it is introduced. It was so beloved by Europeans that after Thomas Drummond—this phlox’s namesake—sent seeds back in 1835, they were able to select up to 200 different color strains. And, now Rudbeckia hirta (black-eyed Susan) is starting to pop in this planting.

It’s amazing to see all this incredible color right next to the road.

One of my favorite color morphs of Phlox drummondii was this pink with watermelon-colored eye.

My friend Dawn Stover helped create this beautiful tapestry, and besides the usual Texas bluebonnets, it is one of the best wildflower plantings I’ve seen in east Texas. The first time I passed by I was stunned by how good the flowering was on these median patches.

Dawn works at the USDA–NRCS East Texas Plant Materials Center (ETPMC). She shared that the City of Nacogdoches approached the ETPMC in 2021 about doing a wildflower planting in median areas that were difficult to mow along the four lane leading north out of the city. She worked with the Texas Natives Seeds Project to create a blend of species that would work well in this area. Here’s a full list of the species included in the mix.

ANNUALS AND COVER CROPS

• Gaillardia pulchella (Indian blanket)

• Rudbeckia hirta (black-eyed Susan)

• Monarda punctata (spotted beebalm)

• Phlox drummondii (annual phlox)

• Hordeum pusillum (little barley)

PERENNIALS

• Asclepias tuberosa (butterfly milkweed)

• Coreopsis lanceolata (lance-leaved coreopsis)

• Penstemon digitalis (smooth beardtongue)

• Pycnanthemum tenuifolium (narrow-leaf mountain mint)

• Rhexia mariana (Maryland meadow beauty)

• Eryngium yuccifolium (rattlesnake master)

• Solidago rugosa (rough goldenrod)

• Symphyotrichum laeve (smooth aster)

• Mimosa strigillosa (herbaceous mimosa)

NATIVE GRASSES

• Schizachyrium scoparium (little bluestem)

• Andropogon gerardii (splitbeard bluestem)

• Bothriochloa laguroides (silver bluestem)

• Bouteloua hirsuta (hairy grama)

• Eragrostis secundiflora 'El Reno' (red lovegrass)

• Bouteloua curtipendula (sideoats grama)

• Eragrostis trichodes (sand lovegrass)

• Sporobolus cryptandrus (sand dropseed)

• Elymus virginicus (Virginia wildrye)

They prepped the site in the summer of 2022, and seed were sown this previous February. In naturalistic design, we call this approach a randomized mix where seed are broadcasted over an area, and plants establish where conditions are favorable. Changes across a site like a slight wet spot here or a subtle change in pH there can cause a shift in what species thrive. And, a plant’s presence or absence can be further shifted by varying the seed mix concentration across the site.

Of course, the ruderals are quite happy, and under their cover are the other species bulking up. Dawn shared that the biggest challenge has been people trying to pick the flowers, which is not good as the plants need to be able to go to seed for next year. The area will be mowed after the spring flush has been allowed to go to seed. And, eventually as the other perennials and grasses begin to dominate and leave less room for the ruderals, this wildflower planting will be more subtle.

As conditions change across the site, species shift. Notice how there’s less Phlox drummondii running through the middle of the planting.

This planting reminds me of the Tower of London Superbloom that we saw last year while in England that was designed by Nigel Dunnett. While that planting was ephemeral as part of a celebration of the queen’s platinum jubilee, this installation is more permanent.

England Superbloom

Texas (mini) Superbloom

And, I think that seeing this mini-superbloom in east Texas is a reminder that ruderal mixes are possible in a variety of different habitats. I have the hope that one day our roadsides will be viewed as not a place that needs to be constantly mowed but a space where we can have ecology and beauty for creatures big and small. And, I believe that plantings like these are just the start of better things to come.

Late April at Ephemera Farm

The spring plantings here at Ephemera Farm are the best they’ve ever looked. The perennials have matured, and the matrix species have knitted together. Even though the Baptisia alba took a hit from the freeze we had, their lack of floral dominance has allowed other species to shine.

I call this first area I’ve developed the light beds for the way that the sunlight interacts with it throughout the day. There’s so many opportunities to see magic from the dew glistening from sunrise to the warmth of the last rays as the sun sets below the tree line.

There are three beds near the house totaling approximately 1,300 square feet with two mulched pathways leading through them away from the house. Where two beds are now turf grass and an old satellite pole occupied the spot when we moved in. I treated the beds as independent at first and a holding ground for species that I had been carrying around in pots for a while. But, they felt too disjunct. Therefore, I killed the grass pathways in between, made them more narrow, and mulched them with hardwood bark to make them feel more cohesive.

And, I unified them with color. I was inspired by the native wildflower color palette I’ve seen on our roadsides, and used species that feature pink, purple, blue, red, and white, and variations on those hues. I decided for these beds to primarily keep the yellows and oranges out. I would say that 90% of the species in the beds are natives.

I’ve used mulch to make things tidier. I realized that mulch is a bit like Powerpoint or a hammer, a tool that if overused can make things look terrible, but when used with good technique could be an ally. A thin layer and the matrix species like Carex and Sporobolus knitting together has helped keep the weed pressure at bay.

Enjoy these photos from the light beds in late April.

I love pausing at these photos and thinking about where does the eye go? This photo was taken on April 23, and the Penstemon digitalis (foxglove beardtongue) had just started blooming.

But, six days later on April 29, Penstemon digitalis was in full bloom creating a frothy effect in the planting.

A little further into the beds gives a different perspective. The matured Magnolia laevifolia on the right helps to hide the air conditioner.

The light beds, looking toward the house. I use fallen branches found on the property to line the bed edges.

I primarily grow Rudbeckia maxima (giant coneflower) in the back of this bed for the glaucous foliage.

Looking west the beds continue to effervesce with Penstemon digitalis.

I love how the purple Streptanthus maculatus (clasping jewelflower) rises out of the bed in the background.

Emergents like Arnoglossum plantagineum (prairie Indian plantain) and Penstemon murrayanus (scarlet beardtongue) add another dimension to the planting by occupying the upper layer.

Penstemon murrayanus is one of my favorite spring wildflowers. I don’t know of another plant that embues the green, blue, purple, and red side of the color wheel so well.

Ruby-throated Hummingbirds love Penstemon murrayanus as much as I do!

Phlox pilosa ‘Bonnie’s Pink’ (downy phlox) is a great seasonal filler for spring. It is an aggressive spreader, which means that it can quickly fill a spot where it is planted. And, the swallowtails seem to love it more than my wild Phlox pilosa selections.

We found some purple-foliage Tradescantia gigantea (giant spiderwort) in Central Texas a few years ago, and it has grown well in east Texas, usually fading out as summer approaches.

The flowers of Tradescantia gigantea (giant spiderwort) are wide open in the morning and on cloudy days. The darker foliage pops against the green.

Not everything is beloved for the blooms. Here Rhus aromatica (fragrant sumac) provides a verdant splash with a matrix of Carex texensis underneath.

I love the subtle color echoes of the rusted stems of Pycnanthemum tenuifolium (narrow-leaf mountain mint) and Arnoglossum plantagineum.

Penstemon laxiflorus (nodding penstemon) is a reliable source for spring color. I have to give them a haircut before they flower to keep them from lodging. It’s hard to do with flower buds already on the plant, but a late March chop results in later blooms and more compact plants.

Ruby-throated Hummingbirds also love Penstemon digitalis. I enjoy watching them flit around the blooms.

One final sunrise shot as we head into May.

Arnoglossum plantagineum | Prairie Indian Plantain

In the spring for herbaceous plantings, I look for species that can grow tall fast and offer substance in the upper design layer. It’s quite easy to find candidates in summer and autumn when the plants have used months worth of sunshine to reach for the sky, but in spring it is a bit more of a challenge. Perennials are starting from ground zero, and to achieve any height, they must be using stored energy from last year.

I have waxed long about how Baptisia alba (white wild indigo) is one of my favorites for height in early spring, but I’m always looking for diversity in that upper layer. Enter Arnoglossum plantagineum, or prairie Indian plantain.

I first saw it out in the pastures here in east Texas, rising out of the lowly grasses and forbs. It was pretty easy to see when it was feet taller than the surrounding vegetation. I could see how this plant evolved to quickly rise up and spear its way through the detritus of the last growing season. It is native from Texas up through the plains states into Canada, where interestingly it is endangered. One would think with climate change it is finding new spots to colonize there, but there’s always development with which to contend.

For me it serves as a primary plant, an anchor in the planting that offers multi-season interest. For the first month after emergence, it looks like a Hosta growing in full sun, hence the epithet plantagineum for the resemblance to the plantain family’s leaves. Even Arnoglossum references the foliage. It means lamb’s (arnos) tongue (glossa) in Greek.

The basal rosettes are a rich green and are a bold presence. I’ll have a hint of slug damage here and there, but so far it hasn’t been very detrimental. And, with the recent freeze, I can say they tolerate 26°F for a couple of nights ok, rebounding the next morning.

Then, the center begins to elongate, it’s pinstriped green and red stems grow up and up and up to reach a height of 4-to-5 feet tall within a month. Such an awesome native plant must be stylish in its rise to stardom.

In bud it reminds me of angelica going to seed, but once the flowers open, one might begin to recognize it as a member of the aster family. They appear as small head inflorescences minus the showy ray florets. Overall, I’m amazed because much of this plant looks nothing like an aster, but I suppose since it is such a radiative family, there are a few odd ball cousins.

The stalks will last into the summer until eventually the whole plant fades away. But, not before the dandelion-like seeds take to the air and sow themselves around. Each year, I find early in the spring new little seedlings that have the promise to rise like their parents and one day command the upper echelon of a prairie or planting.

The Blessing of Seedheads

Today looks cold enough to snow with the low gray sky. I’m more used to this weather in February than I am November. The forecast said the high won’t break 50ºF today. Alas, the only thing falling from the sky will be rain.

I do a final walk around before the clouds burst. We’ve now had a few frosts, one hard one this past weekend. Looking out over the garden, most of the flowering plants are now done. I’m afraid even my late flowering ‘Halloweenie’ glads (Gladiolus dalenii) that haven’t bloomed yet (and with their tardiness in past years I’ve joked should be named ‘Thanksgivingie’) are going to get hit with more freezing temperatures we have coming this week.

So on this walk I’m thinking of frost-proof winter interest I have for the next few months in the garden. I’m counting my garden blessings if you will to see what at the end of the season I can appreciate.

Seed heads are at the top of the list as they have such a prominent presence in the winter landscape. They are skeletons of the past that, a glimpse of what the garden once was in the height of its empire.

Near the house Helianthus radula (rayless sunflower) still looks spectacular as the black stems pop against the froth of Eragrostis spectablis (purple lovegrass, header image). On the other side of the lovegrass rise the black buttons of Pycnanthemum tenuifolium (narrow-leaf mountain mint). It is one of my favorite perennials for its multi-season interest in the landscape. I make a note to pair more blacks with the winter foliage of the love grass for next year.

There are also some Lilium formosanum (Formosan lily) in the bed that rise up and have started to release seeds from their brown chalices. I just transplanted them to that spot this spring, so their height is much shorter. I quite like their more diminutive nature.

Pycnanthemum tenuifolium

Lilium formosanum

As I walk further along the bed, I see the spherical seedheads of Hyptis alata (clustered bushmint). They will last the rest of winter, though I have to be careful whenever I remove them come spring because they are loaded with seed that I’ll be weeding for months afterwards if they spill.

Hyptis alata

Nearing the orchard, I startle some Dark-eyed Juncos. They are the first I’ve seen this year, and I’m delighted the cold fronts have brought them back to the garden. They dart under the glimmering split-beard bluestem (Andropogon ternarius). Even on a sunless day, the plant still shines. The clumps are now in their second year, and I realize the site I put it on is too fertile as some have lodged and thus made an even better hiding place for the juncos and other little brown birds mixed in the flock. Next year, I’ll have to cut them back in mid-summer much like they do when mowing the roadside to help keep it shorter for lasting winter interest.

Andropogon ternarius

There are still a few Baptisia alba (white wild indigo) in the orchard beds. For us they start going dormant in late August or early September. It’s always a hard call for me to ask do these dead twigs stay or do they go. But, I seem to always err on letting them stay. Some have already blown away with their tumbleweed action, and I have found them next to a fence or in the ditch by the road. It’s a creative approach to seed dispersal.

Another Baptisia, yellow wild indigo, is nearby in the front of the patch and has more spherical fruit, hence the epithet sphaerocarpa for the round (sphaero-) fruit (-carpa) it forms.

Baptisia alba

Baptisia sphaerocarpa

Vernonia baldwinii (western ironweed) also looks good in its last moments. I have found they have staying power into the winter with their feather-duster seed heads. The pappus is such a nice light tan and pops against the dark stems.

Vernonia baldwinii

A flock of winter birds is once again startled as I make my way back toward the house. I think how seedheads are not just a blessing for me. I know that the winter birds enjoy them, too. That’s why I admire them while I can before they and the wind spread the seeds. Such thoughts warm my soul, perhaps as much as the corn chowder I’ll have tonight after a cold autumn day.

Superbloom

I love wildflower eruptions. I’ve witnessed these floral spectacles a few times in my life. An Appalachian forest floor covered in Phacelia, the roadsides here in the lone star state littered with Lupinus and Castilleja, and a bottomland hardwood forest so thick with Packera I could barely walk are a few that come to mind.

And, this summer, what were the odds? We booked a trip to England the same year that a superbloom was going to be planted in the moat surrounding the tower of London. Of course, superblooms are more intense than just a showy patch of wildflowers. They are a product of nature, the perfect environmental conditions causing all seeds of handful of denizens to erupt into bloom, usually carpeting the barren desert. Some superblooms are even visible from space.

However, this Superbloom was one made by man, a flora synthesized from species around the world to create a spectacle celebrating the Queen’s Platinum Jubilee. Nigel Dunnett designed the planting to make the Superbloom in the moat surrounding the Tower of London happen this summer. Over 20 million seed were planted and nurtured to be enjoyed by countless visitors.

While visiting London in July, we made a point to visit the Tower of London Superbloom. It was a wonderful case study in seeing the end result of synthesizing a naturalistic planting from seed. While I had seen naturalistic plantings developed from plugs and gallons, I had yet to really see a seed-based system. Such systems are more open to randomness and plants appearing where environmental conditions suit them. Thus, I tried to pay attention to the little details throughout the planting.

I have to had it to Nigel and his team. The bloom was probably at the closest to peak as we could have experienced it. And, bringing a superbloom into the heart of London I hope only inspired and educated people about the power of plants.

ENTERING THE SUPERBLOOM

We arrived right after they opened and thus beat the crowds. I was aware of the calm colors used at the entrance—whites, soft yellows, greens, browns, and blues with a few other pastels mixed in.

The view walking into the superbloom. Notice how the colors started soft and mellow. A pathway allows exploration, and a kettle hides a grate.

Here we see pops of color, but overall the planting isn’t too intense.

Woven willow added legibility between path and flowers. The introduction of oranges from Calendula, Dimorphotheca, and Eschscholzia add some pop to the planting.

SUPERBLOOM SLIDE

I mean, if you’re going to have a superbloom, you might as well have a superslide, right? Near the entrance was a fun way to get kids more engaged with the space.

The planting around this structure was my favorite of the experience, I think because of the layering, texture, and color. Verbena bonariensis and Oenothera (Gaura) lindheimeri both provided this moving, emergent layer above the umbels and asters below. In this section it was clear that plugs had been introduced as we saw Kniphofia, Sedum, Stachys, Agastache, and other plants that had significant biomass that would have unlikely been achieved in one growing season from seed.

Wildflower plantings around the superslide.

I was quite fond of Verbena bonariensis and Oenothera lindheimeri early on in the display. Here it was evident they had used plugs to bolster the underplanting.

I also admired the verticality of the Agastache inflorescences.

Here you can also see the diversity in this initial section.

The Verbena bonariensis faded away as we approached the mass planting on the western side of the Tower of London.

THE WEST SIDE

Past the superslide was a large open area where the flowers formed a living tapestry. Blues of Echium vulgare and Centaurea cyanus softened our approach to the more vibrant oranges and yellows . It was shocking seeing so much color after the cooler colors of the Verbena and Gaura section.

You can see the shift in color and planting here as the blues and purples gave way to the yellows and oranges.

Atriplex hortensis ‘Rubra’ emerged from the golden haze of wildflowers below.

The eyespots of Coreopsis tinctoria were a nice color echo with the Atriplex hortensis ‘Rubra’.

Further from the Atriplex hortensis ‘Rubra’, sunflowers were used to provide the emergent layer.

As we walked on, other colors were mixed back in to give the eyes a break from the yellows and oranges.

This photo is one of my favorite shots of the superbloom for the diversity of colors and species.

It truly is amazing thinking that most of this developed from the planting of 20 million seed.

One of the few sections of the superbloom that we saw where things were beginning to be past prime for color. The seedheads were noted to be important for birds.

In this western section, it became clear that the superbloom was designed to be an immersive experience. While the path was off to one side, there were these small circular viewing areas that allowed visitors to step into the space.

You can see there are a few of these compartments for a visitor’s viewing pleasure.

A photo from the walkway above before we entered really gives a perspective of these puzzle piece edges. I liked how on this western side that the foot traffic was confined to one side so that it really allowed us to appreciate the scale of the wildflower planting.

A close up of one of viewing areas

Karen paused in one of the circular areas for a photo with the wildflower backdrop.

THE NORTH SIDE

As we approached the north side, one of the pleasant surprises we experienced was natural music being played. Erland Cooper who creates natural synth music composed Music for Growing Flowers specifically for the superbloom. It was a twenty-minute looped piece, and you can listen to it here. It was a delight to hear the music over the bustle of the city, and it made me ponder why we don’t use music more in gardens?

On a sign he said, “I plough themes of the natural world for inspiration and wanted the ambient score to feel conducive to a growing environment. As music is just vibrations of sound, I’d like to think that it is encouraging the flowers to grow in their life cycle over the summer, boosting biodiversity and helping on this rewilding journey.” A lovely thought indeed.

I really admired the efforts to educate the public with the signage provided. Below is just one example of many that communicated the dynamics of the superbloom site.

While I took photographs of many of the signs, I chose to share this sign specifically because it alludes to the changing conditions for establishing seedlings on the site.

I noticed that in one area, the seeds seemed to have a hard time getting established. I asked a volunteer about it, and he said that heavy rains in March had washed some of the soil away.

While I was standing looking at this space, I saw a demarcation line between a big expanse of yarrow and the seed-sown wildflowers. It hit me that I was looking at wildflower sod.

As the sign alluded to above, there were establishment issues in the spring, and so I assume that wildflower sod was brought in to fix that issue. I think the first person I heard using wildflower sod was Carrie Preston at the 2017 Philadelphia Flower Show. This section of the Superbloom was the first time I had seen it used in person, and I thought it a brilliant backup plan because I’ve had issues with getting seed to establish via direct sowing, too.

Here you can really see the sod line on the yarrow and the lack of establishment from the seed.

This photo is a shot right behind the one above where you can see the sod line. Isn’t this mass of Achillea lovely? My guess is that at least part of this was established using wildflower sod.

I was also very curious about these patches that were devoid of any flowers that I saw at the Superbloom. They were mainly on this northern side of the Tower of London. I noticed them before we entered from the walk way above. At first, I thought that they had cut the wildflowers back for regeneration, but once on the ground I realized I was wrong.

I don’t think that the bare spots detracted. They served as breaks in the superbloom, areas where just like in nature the wildflowers aren’t as abundant.

Instead, what I was seeing was fresh wildflower sod that had been laid. In some areas it was more established than others. My guess is that as sections have petered out or had poor establishment, the sod is an opportunity to replace those areas. I had wondered how one could keep such a spectacle going, and so these observations helped make more sense, though I’m not suggesting they used the sod over the entire area. I really think they had crafted a mix for long season interest. But, if the seedlings don’t take, this technique is an option for a bandaid for these styles of plantings.

A close up section of wildflower sod that looks recently laid down. I can make out what looks like the silver-leaves of Lychnis and the emerging feathery foliage of Achillea.

A patch of wildflower sod from a broader perspective. Notice the overall brown coloration, and compare with the photo below.

Here is another section of sod that is more established. Notice how much more verdant this space is.

I share all this not to detract from the Superbloom or to degrade it but to share the nuts and bolts of how it is managed. As I said earlier, seeing it in bloom is a wonderful case study for learning, and I am fascinated by such minutiae. I admire the creativity to have options to keep the space looking fresh and alive.

THE EAST SIDE

As we walked eastward, we began encountering small hillsides of wildflowers. Yet another way to make the site more engaging was to create changes in elevation for the wildflowers, which was achieved by bringing in soil and sowing seed on these raised areas.

Here you can really see the elevation change on this hillside. You can barely see the people on the other side who are standing on the pathway.

What I liked about the elevation change is that it brought many of the wildflowers up to face level, so that instead of looking down one looked toward them.

On the far northeast side was a beautiful willow sculpture called Nest by Spencer Jenkins. Having structure in the Superbloom gave it a sense of permanence, even if it was made from natural materials.

I’m a sucker for woven willow, and Nest by Spencer Jenkins was a lovely homage to the animals that share the space with wildflowers.

This vantage shows how the curves of Nest blend well with the sways in the planting beyond.

The last section had a vegetable garden feel. There were enclosed spaces with winding pathways. The incorporation of dill and sunflowers added to the allotment feeling. It was as if the design communicated, “I’ve taken you through what it might look like in the wild, and now let’s consider how we could incorporate these ruderals into our gardens, big and small.” In this space there was a nice pollinator display with woven branches and metal sculpted pollinators above.

This space looked like a summer vegetable garden erupting with growth.

More willow structures added to the organic feel of the site.

Papaver, Anethum, Centaurea, and Echium were the last big dominant species in this space.

Another shot of the wildflowers at the end of the Superbloom.

Artist Mehrdad Tafreshi made these cool brass and copper pollinators that hovered over this last section.

SUPERBLOOM AT NIGHT

We had a glimpse of the Superbloom the night before we walked through it. My colleague Andrew Bunting of the Pennsylvania Horticultural Society had visited only a week earlier. I saw his incredible twilight photograph on Instagram, and I knew we had to visit in the evening. I snapped a few photos just before sunset. It was really something else to see lit up at night.

An almost duplicate of the image I saw Andrew post a week prior to our visit. Seeing the Superbloom early before it got crowded was on my itinerary, but after seeing his photo, I knew we had to visit at twilight, too.

It was amazing to see how the wildflowers at night glowed when shined with colored lights.

A photo of the eastern side of the Superbloom glowed under purple lights.

One of the things about wildflowers is they not only catch sunlight but they also are great at refracting light at night.

The July 2022 super moon shined over the glowing Superbloom.

After the experience, I thought it funny. I’ve never been out west to see the famous California superblooms, and here I have traveled a quarter the way around the world to see one. And, just like many of the superblooms here, this display was ephemeral. It won’t last much longer with the close of summer upon us.

But, the memory of such sights lasts. I hope that with this photo journey you feel inspired at such a massive display of wildflowers, too. It makes me think about how I can incorporate more ruderal plants into my garden to make a mini-superbloom of my own.

Lessons from Leuvehoofd

It was cool gray June day when I hopped off the train in Rotterdam. I was in the Netherlands for a soilless substrate conference in Leiden, almost ten years ago now. While there, I took the time to explore local gardens. Of interest to me were plantings that Piet Oudolf had designed in the city along the waterfront. One was found at Leuvehoofd, a park right on the Nieuwe Maas or New Meuse River.

Planting: A New Perspective by Piet Oudolf and Noel Kingsbury had just come out, and I snagged a copy before heading across the ocean, reading it furiously on the flight and during down time in the hotel. It was so interesting to have a guide to the planting right in my hands as I was visiting the site.

I approached the park from the south, where a long bed dominated by mixed grasses, Iris, and fading Allium came into view against a monument for those lost at sea in World War II. I would learn it was named De Boeg, which translates to The Bow in English. The memorial stands 150 feet tall with a pair of iron wings at the base that appear to be breaking water.

Iris sibirica ‘Perry’s Blue’ pops against the green foliage of grasses as the Allium above fade.

Turning a photo black and white so helps me appreciate the textures of the site. De Boeg was a war memorial to those lost at sea in World War II, and here it appears to be breaking through a colony of floating jellyfish

Here you can see how the naturalistic planting softens the starkness of the memorial.

From there four angular beds rippled out from the monument like waves getting larger until they hit the river’s edge. I quickly noticed that the planting this time of year had an overall cool color scheme of blues and purples. For a bit of brightness, down the center of the planting ran a river of Deschampsia cespitosa ‘Goldschleier’. Walking around the garden was interesting because viewing it from different points allowed me to see different perspectives and plant combinations.

Years ago, I downloaded several images from Piet Oudolf’s website to be able to study the designs. The one above is of an early rendition of Leuvehoofd that I cropped to show the four primary beds of the planting.

A perspective showing the essence of the planting at Luevehoofd Park. It is mostly a sea of green dotted with blue Amsonia, purple Allium, and the strip of Deschampsia.

One of my favorite photos from this experience was this view of the planting right next to the water with the Erasmusbrug or Erasmus bridge in the distance.

From this angle you can better see the mass of Deschampsia cespitosa ‘Goldschleier’ that runs through the center of the planting. You may notice on the drawing above that Sporobolus was recommended, but in the book Planting: A New Perspective, Deschampsia was mentioned instead. It was a nice glimpse at the iterative nature of developing a planting.

An unknown light blue Iris softens the sea of green. The design had called for Iris siberica ‘Perry’s Blue’, but it seemed that a few different blue variants were mixed in to play off the analogous color scheme.

A long view of the largest bed along the river front. The scattering of the Allium is quite apparent here. From this view I also really began to appreciate the presence of the matrix or groundcover level out of which other perennials arise.

Calamintha served as a skirt around Amsonia.

I also admired Piet’s ability to create combinations between plants to elevate the planting. This topic was one that Thomas Rainer and I discussed on the recent podcast, these small decisions about color, texture, and/or plant form made when pairing plants that really show the artist’s touch.

Here the colors of rosy purple Salvia nemorosa ‘Amethyst’ echo the umbels of Allium christophii.

Spires of Salvia nemorosa ‘Amethyst’ rise from a block within the planting.

Another example of color echo was between Allium christophii and Sedum ‘Matrona’. Both have hints of that smoky purple hue.

I also admired the repetition of starry shapes in parts of the planting. For example, here the stellate flowers of Amsonia are similar to the stellate flowers of the Allium. Perhaps they seem minuscule, but I believe such small choices are instrumental in elevating a design.

One final shot showing the blending line between the mass of Deschampsia cespitosa ‘Goldschleier’ and the mixed planting.

Overall, it was a good first introduction to a Piet Oudolf design. Leuvehoofd was moderately sized yet digestable. In the coming weeks, I’ll post a second planting I saw right down the river at Westerkade along with the lessons I learned there.

True Grit: Planting a Gravel Garden with Students

“How did I get here?” I asked myself in anxious jubilation last Friday as I watched the dump truck release its load of 6 cubic yards of gravel behind the agriculture building. The driver, a super nice guy named Mike, wished us luck on planting our gravel garden as he drove off. He had never heard of growing plants in gravel. And, up until a few years ago, really neither had I.

But, the rhetorical question really made me reflect. Why was I having students plant common perennials in gravel?

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Every two years I teach Herbaceous Plants, a class devoted to the annuals and perennials that will do well in east Texas and the southeast. This semester is the fourth time that I have taught the class, and each year I get a little more focused on the use of these plants in naturalistic design. In the past years, I’ve had students design and plant prototype designed plant communities in our edible garden. We deemed these food prairies since the garden was centered on food for people, and these plantings would provide food for insects. They would also provide food for the mind where the students and I could learn better how to do this sustainable type of planting.

Through the installation of naturalistic plantings, I’ve realized that the weed management is a constant struggle. While weeds are already a challenge during the active growing season, they are also problematic during the cooler months here in the southeast when the weather is mild enough to allow persnickety winter weeds to continue growing. The hope with naturalistic plantings is that they can close quickly enough to choke out potential weeds, and if the weed bank is depleted prior, it certainly helps. But, management often requires the use of mulch, pre-emergent herbicides, and/or wedding to control such issues. Other friends and colleagues have commented on their frustration that weed management after installation can be quite cumbersome especially with the dense planting used.

A Permanent Mulch

In my studies of naturalistic design, I’ve learned that weed management can be induced by increasing the stress of the site conditions and by lowering the level of nitrogen in the soil. An inorganic mulch layer of gravel, sand, recycled concrete, or other crushed aggregates achieves both of these goals. I first became aware of the science behind this approach when I heard Cassian Schmidt speak at the 2016 Perennial Plant Conference. He had detailed data down to minutes per square meter on how much management must occur for different types of plantings, and rocky soils that create more stressful conditions for the plants reduce management time. I realized I had seen these types of plantings before. I had visited Beth Chatto’s gravel garden in England where famously none of the plants have been irrigated. And, of course the gravel garden at Chanticleer has always captured my attention.

The gravel garden at Beth Chatto’s nursery in the UK was once a parking lot. It now features denizens from around the world that survive in more stressful conditions.

The gravel garden at Chanticleer hosts a wide range of species that tolerate growing in harsher conditions.

Hearing Cassian Schmidt’s presentation really piqued my interest in using gravel as a planting medium, but I had my doubts. I really hadn’t embraced that stress was an asset yet as I had studied about emulating nature in the other direction and enriching soils with organic matter to prevent problems with edibles. I started to think about the plant communities I had seen in west Texas or the North Carolina barrens. Perhaps it was possible, and we could make garden soil more stressful for plants.

I started looking for more information on the subject. I learned about Peter Korn and how he grows plants in straight sand conditions, and again, I was amazed that plants could survive in such a scenario. In 2019, I attended the Perennial Plant Association’s (PPA) meeting in Chicago, and on a tour visited Olbrich Botanical Gardens where Jeff Epping is director of horticulture. Right off the bus was an incredible perennial planting at the entrance. I would discover from the conversations of the people around me that the thriving plants I saw were planted in 4 to 5 inches of gravel! Once inside, we would discover other gravel plantings where Jeff had overseen their install. I’ll add here that I’ve learned much from looking at a presentation he gave at PPA in 2017.

Perennials thrive in a gravel garden at the entrance to Olbrich Botanical Gardens.

Here’s another gravel garden further in Olbrich Botanic Gardens that features Calamintha, Sporobolus, Allium, and other species.

Around the same time, I was delighted to see Ben O’Brien have success with planting in combinations of sand, gravel, and recycled concrete in Canada. He did some incredible trials of different species in these mixed aggregates, and the complete results of his work including a species-by-species breakdown of his trial can be found on his website.

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HOW WELL DO GRAVEL GARDENS WORK IN THE SOUTH?

But, most of these plantings are found up north—Wisconsin, Pennsylvania, Ontario, England, Germany, and Sweden. The question is will they work in the deep south where we get quite hot later in the summer and can have prolonged dry periods. And, again I’m not focusing on xeric or alpine plants but instead common perennials to grow in gravel.

So, I decided with my class this year that we would install a gravel garden to attempt to answer this question. This class would be slightly different because due to COVID-19 we condensed the class from16 weeks down to a half semester of 8 weeks. We would just double the time we met each week to cover the same material. But, that also meant we had to expedite the process of developing the garden.

I should also note for those of you concerned about my students or me in a COVID-19 environment that I have been extremely cautious. (I’m that cautious person who hasn’t eaten out in a restaurant since March 2020, hasn’t travelled to see family or really anywhere, and was told back last spring when I was rearranging my classes that I “drank the Kool-Aid” about the hyped-up concerns over COVID-19.) There were only seven students in the class, which allowed for social distancing through this entire course, and students wore masks as well, too.

Here is the site of our future gravel garden at the bottom of Sprout, our edible garden in the Plantery. The Plantery is our teaching gardens, grow houses, and micro-farm Sprout located near the SFA Agriculture building where we can provide students with hands-on learning opportunities.

Prior to installing the garden, I covered many of the basics of naturalistic design from competitor—stress-tolerator—ruderal survival strategies to Nigel Dunnett’s FLOW design method in class. Students easily understood Nigel’s classifications of anchors (primary plants in the installation), satellites (plants that provide seasonality around the anchors), matrix species (the groundcover species, typically grasses), and free floaters (self sowers that pop up here and there). We then practiced iterating and creating naturalistic plantings, first as students in small groups and then as solo projects.

For our gravel garden, I provided students with a plant list of species that we had both ordered and propagated. Normally, we would choose the plants early in class and then order them or grow them, but the shortened semester forced my hand. I also provided students with a rendering of the site dimensions where the students were able to apply what they learned in class, and from a measuring lab we determined that the full sun site was approximately 400 square feet in size. Below are two anonymous examples of the drawings that students developed for the class.

From these drawings I then synthesized them into one cohesive design. Again, normally, we would do this activity in class, but with the time limitations I decided to render the design myself. The design we went with was to have taller edge species at the back of the planting near the fence that my nursery management lab had built the previous fall. Then, a sinuous curve would snake through the bed with plant anchors and plant satellites arranged on either side of the bed. Some large rocks remained in the bed from a previous planting that students like to sit on and take pictures, and we decided to just use them as part of the design. The taller species would provide a nice floral backdrop and the pathway would pass right by these larger stones.

The biggest challenge was sourcing the mineral mulch. I had almost given up when I found a company in town that sold baked clay that is used on roads, and it appeared to be clean of weeds, had the angular size of grit that we desired, and had that gray-blue color that I had seen before at other gardens. It was a bit pricey coming in a $110 a cubic yard, but I was prepared to pay for good quality material. This gravel was delivered last Friday in anticipation of planting this week.

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TUESDAY MORNING CLASS, SPREADING THE GRAVEL

We finished leveling the soil in our morning class. We then put stakes in that had two markings, one for the soil line and one for the gravel line. Students then began to spread at least 4 inches of gravel over the entire site. We then went back and checked with trowels to make sure that the gravel depth was right over the bed.

A view of the site from the ground prior to any gravel. Oh, and in case you’re curious about the white in the Sprout garden, those are floating row covers over tomatoes. We had a freeze forecasted this week!

Students begin spreading gravel over the site.

The stakes really helped us check the gravel depth.

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TUESDAY AFTERNOON LAB, PLANTING THE ANCHORS AND SATELLITES

In the afternoon lab, we flagged our pathway and then began placing the the anchors and satellite species into the bed. I paired students off to look at the design and then place plants appropriately with notes on how many plants should be placed in each area. From reading about gravel gardens I was aware that we needed to knock off excess soil to decrease the organic matter in the bed and remove the top of the substrate from the rootballs to reduce the weed load we might be putting in the beds. So, when we began planting, I instructed students to use Tubtrugs to accomplish these tasks and not get soil in the gravel. Afterwards, we watered the plants in well.

Students begin setting out plants based on the design.

Mike and Hanna check the design for the placement of Symphyotrichum oblongifolium ‘Raydon’s Favorite’.

The anchors and satellites laid out prior to planting.

Brendan plants a Pycnanthemum tenuifolium into gravel.

Nyree knocks the soil off a Pycnanthemum tenuifolium plant.

Hope waters the plants in after planting.

The anchors and satellites planted into gravel.

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THURSDAY MORNING CLASS, PLANTING THE MATRIX

We wrapped up the planting Thursday morning by planting the matrix species. We planted more Nassella, and then we introduced a few Sporobolus heterolepis in the front and Muhlenbergia reverchonii in the back. We also scattered Echinacea purpurea and Echinacea purpurea ‘White Swan’ through the latter last two grasses to see how they will do on site as self sowers.

Planting round two begins with installing the matrix layer.

The gravel garden fully planted!!! Yay!!! We still haven’t decided what edging to use to mark the path. We may wait until the plants fill in a bit to determine that. We are thinking willow, bent metal, or maybe just leaving it bare.

An overview perspective of our new gravel garden. And, in case you are wondering about the area to the right of the gravel garden that’s been recently cleared, we eventually want to turn that into a practice patio garden where students can overhaul it every few years. Since we are a small program with limited funds, we tend to piecemeal projects together. This gravel garden pathway will feed right into the space as if it is part of an extended back yard to the mock patio.

As Jeff Epping suggested in his presentation, we will irrigate often for the next several weeks until plants are established. And, reflecting back over the whole process the one change I want to make is to try to find cheaper gravel that achieves the same effect as this baked clay product.

I look forward to seeing the true grit that these plantings will offer for us here in the southeast. I asked students what they loved most about this project. Common comments were how good it looked at the end, learning that plants could grow in gravel, and the excitement to see how the planting will look in a few months. I, too, have that same excitement, though with a dash of the fear of failure. But, I know that failure feeling is essential when trying something new that pushes the boundaries of what is possible and learning new things about horticulture. And, as I kidded with the students, should this fail, well, we have 6 cubic yards of gravel for our future walkways! :-)