Autumn Sowings and Spring Seedlings

And, just like that, March is here.

If I’m honest, spring has crept up on me. Maybe it’s the travel for plant presentations or the busyness of fatherhood.

We were also 17 °F and 23 °F two mornings a couple weeks ago. The cold is still fresh on my mind and still tangible in the soil.

But, the warming days are spurring growth along. All around us the earliest wildflowers and ephemerals are emerging right on cue with this first week of March.

With the growing to do list of spring, I’m glad that I’ve been preparing for this growing season. Much of the prep work we did earlier in winter readying the garden for spring is now paying off. Transplants are rooting in and emerging, clumps I divided are producing fresh shoots, and autumn-sown seedlings are revving up their growth.

With new species where I’m learning the knacks of propagation, I like to autumn sow wild-collected seeds outdoors in trays or pots to mimic natural conditions. It helps me understand if that practice is enough to have successful germination or if I need to craft a better strategy.

While some seeds are just now sprouting, others have been growing all winter and capturing the precious sunlight of short days to be ready to pounce once warmer weather arrives.

Scutellaria integrifolia (helmet skullcap) seed was new to me this past fall. It’s a great spring flowering native with rich blue flowers.

Scutellaria integrifolia (helmet skullcap) flowering

Scutellaria integrifolia seedlings

Once it finishes flowering, it produces these little tractor seat capsules that release seeds. And, last fall I collected some seed here in east Texas. Mid-November sowings had visible cotyledons in early December, and now plugs are plump and well rooted to provide more spring color.

I’ve been wanting for a few years to acquire the local evening primrose species Oenothera rhombipetala (four-point evening primrose), and last fall, I finally had good luck finding the dried seed capsules on a sandy hill nearby. Seeds were sown in mid November, and by the end of the month they had already germinated. I watched as they would tinge maroon with each passing cold snap only to green up with warming weather.

Oenothera rhombipetala (four-point evening primrose) flowering

Oenothera rhombipetala seedling

I spent this week planting out both species in the garden along with Steptanthus maculatus (clasping jewelflower). While I have seedlings that pop up here and there, this calciphile usually needs a dusting of limestone in the hole to provide good growing conditions in our acidic soil. So, I find growing my own seedlings in winter and then transplanting them out a good way to ensure success.

Some of you may have noticed the unique trays I’m using to grow seedlings. I really like these Winstrip trays from Neversink Farm for seed propagation. The airspace helps to root prune rootballs so they are ready to grow once put into the soil. While I recognize plastic trays are a problem, one approach is to purchase extremely durable trays that will last years longer than thinner options. And, seedlings pop out the empty bottom very easily for transplanting.

There are other signs of seeds sown last year germinating. Trillium, Silphium, Rudbeckia, Asclepias, and more are breaking dormancy with the warming weather. And, now with the time change, we have more light and more time in the evenings to enjoy the garden, plant seedlings, and watch them grow.

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KEEP GROWING

Native Wildflower Seedlings of January

It’s a new year, and even though we are mere weeks into winter, I can already see new life has begun to stir in the garden amidst the detritus of the previous season. And, even though much of the garden has gone brownscale, there are sparks of green appearing at the ground level. The verdant threads of Muscari and Ipheion foliage are weaving themselves through the grays, browns, and tans of last year. And, Achillea millefolium (yarrow) clumps are so robust they are throwing up flowers.

I haven’t quite figured out how to reconcile the green with the brown. In some areas, they seem a bit at odds as if the seasons are competing against each other. It is as if spring has sprung, and I haven’t cut things back yet. I debate should I remove or reduce the green in certain areas.

But, greenery I will never remove are my native wildflower seedlings. They tend to be less conspicuous, and I love seeing these little seedlings tucked under, around, and even in other plants. Their time to shine will come later when I need ruderal color for creating layers in the garden while other plants are just getting going.

And, more so this year than any previously I am ecstatic to see the number of seedlings of native annuals that have established themselves in my beds. It seems that encouraging them has payed off.

Lupinus subcarnosus seedlings

Lupinus subcarnosus in bloom

Last year was the first year I had a decent stand of our more wet tolerant Lupinus subcarnosus (sandy-land bluebonnet). I collected what pods I could from the plants in my garden and stored them in a galvanized bucket in the garage. I was surprised one sweltering afternoon months later when the sunlight hit the bucket just right, and I heard a pop, much like a kernel of popcorn popping on the stove. I figured that drying would have already released all the seed by now, but could heat be an additional requirement? I sat the bucket on the pavement and moments later I heard pop, pop, pop! Seemed so.

Later in autumn a few hours before a good rainstorm, I separated the chaff and scattered it around wilder parts of the patch I don’t get to weed much in case there were some seed I missed. The seed left in the bucket I scarified by pouring boiling water over them. Once the water cooled, I scattered the the swollen brown specks around the garden right before the rain began to fall. I saw nothing at first, but as autumn deepened I started noticing their characteristic cotyledons appearing in the open spots.

I wasn’t able to get my hands on all the pods. A number of them went rogue and sowed themselves into driveway cracks and mulched pathways near the garden. I can’t do much with those in the drive, but those in the path I have been slowly relocating with a sharp garden knife so I don’t disturb the taproot too much.

Steptanthus maculatus seedling

Steptanthus maculatus in flower

I did something similar with Steptanthus maculatus (clasping jewelweed). I collected what seed I could in a box, and then I went around beating the leftover stalks around the blackberries trellises to release what seed I missed. I probably looked like I was doing some ancient seance to any passers by, but nope, I was just sowing seed. And, now their jagged plum rosettes have germinated and gotten quite large this winter. They seem to like germinating in organic matter since they abhor our acidic soils.

Nemophila phacelioides seedlings

Nemophila phacelioides in flower

But, then there were other wildflowers I didn’t even know were increasing in number. I was stunned to pull back a curtain of Muhlenbergia capillaris (pink muhly grass) foliage to find a clump of around 40 seedlings in a bed clustered together that I didn’t quite recognize at first. Then, when I looked at the lobed foliage I knew they were Nemophila phacelioides, and their proximity to the original clump helped me id them. I now had many to transplant around the garden to encourage their spread. I moved a good number of them in December during a good warm wet stretch, and they have settled in well, their tentacle-like leaves stretching out to capture the warming sun.

But, I shall wait to move any more seedlings until after next week’s cold snap. I like to see at least two weeks of not too harsh weather when moving little seedlings in the winter time. That way I give them the best chance at success so that in Januarys to come I’ll continue to see the beds littered with seedlings once more.

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Learn from these similar posts

Streptanthus maculatus | clasping jewelflower

Clasping jewelflower has sent me on a treasure hunt trying to figure out how to grow this beautiful native. After two failed attempts, I’m happy to report that I’ve had success this year with Streptanthus maculatus!

I first learned about this spectacular plant from naturalist Matt Buckingham. He posted on his website about it in 2019. That fall, by coincidence a friend of mine shared some seed with me they had collected further north in Texas.

I sowed them into trays that winter, planted the seedlings out that following spring, and was sorely disappointed to find them get barely above 6 inches tall. They were puny and sad looking. I was intrigued because the scale of the plants in the images that I saw from Matt’s blog looked bigger; however, maybe this height was as big as the plant grew, and he was just using a macro lens?

Last year, I decided to let mother nature take care of things, and I sowed the remaining seed on my front bank under dappled shade, thinking perhaps they weren’t too happy growing in peat or being transplanted. I was delighted when my plants grew and rose to a height of around 18 inches. But, they still looked spindly. My concerns that there was still something wrong were confirmed when my friend Mark Tietz posted some images of three-foot tall plants on Facebook and made me realize that this plant had the potential to get much taller and fuller. In his comments he shared that the plant grew on alkaline soils from ancient seabed sediment.

I had realized in my time at Ephemera Farm that I had better luck with plants if I sweetened the soil with lime prior to planting. Our pH of 4.2 has been rough on many native perennials, some even from just down the road that originally grew in less acidic soil.

Armed with this information, I collected what seed my plants produced on the front bank, and then set about sowing them this past winter. This time, I made sure to start them in slightly larger cells (32’s instead of 72’s). I planted 25 transplants. For most of them, I limed each hole prior to planting as if I was lightly dusting a beignet. The scientist in me made sure to not lime three holes to act as a control. The growth differences, as you can see below, were visible soon after planting.

March 25 2023: The control Streptanthus maculatus without lime added to the planting hole. Plants in the three plugs were stunted in growth.

March 25, 2023: A Streptanthus maculatus with a dusting of limestone added to the planting hole. Notice how much larger the leaves are compared to the control.

And, let me tell you, I am ecstatic to see how well the limed plants are doing this year. Most plants top out at two-to-three-feet tall, and they are loaded with flowers.

I cannot tell you how much joy I got from seeing these Streptanthus maculatus thrive after failed attempts.

And, if you’re wondering how the plants I didn’t lime fared, check out the images below.

A close up of one of the three Streptanthus maculatus plugs that didn’t receive lime. This plant is approximately 15 inches tall, and the other two look similarly bad.

And, a close up of one of a Streptanthus maculatus that did receive lime. This plant is three feet tall, and loaded with 50+ flowers in just one inflorescence!

To me, clasping jewelflower is a native Lunaria without the large translucent seedpods. The clasping name comes from the perfoliate leaves that wrap around the stem. I should note that the plants I have are Streptanthus maculatus var. maculatus with their more lance-shaped leaves. The other variety Streptanthus maculatus var. obtusifolius has more obtuse foliage.

My first Streptanthus maculatus coming into bloom earlier this spring. Don’t you know I was giddy! You can see in this image the opening flowers twist a bit, hence the other common name twistflower.

The two-tone flowers play so well off my already cool color scheme of pink and purple. Note the clasping or perfoliate leaves of clasping jewelflower.

Being in the Brassicaceae family, it has that classic four-petal cruciform flower shape. Another common name is clasping twistflower, which is a nod to the petals that twist a bit as they open. I’ve also had slight issues with cabbage looper worms trying to eat the leaves. A dusting of Bacillus thuringiensis brings them quickly under control. I was concerned about spring storms toppling them. They have bent a bit due to some storms (header image), but overall they are still mostly upright and standing. And, the honeybees LOVE them. Every afternoon they swarm the plants.

I was just fascinated to see how a little bit of lime transformed the growth of this native annual. I dug deeper into this plant’s propensity for alkalinity, and I found an interesting note about the closely related Streptanthus squamiformis (pineoak jewelflower), an Ouachita Mountain endemic. Virginia McDaniel reported in a 2014 edition of Claytonia, the newsletter of the Arkansas Native Plant Society, that they had seen similar scrawny plants in bloom when doing Streptanthus surveys. Then, her friend visited a site that same day that was burned earlier that year and discovered a purple haze of flowers. She stated, “As he climbed higher, the numbers increased and the plants got bigger. Hundreds of individuals were scattered across the mountain side!”

She hypothesized that the fire had created excellent conditions for germination. But, I’m wondering if there’s another effect from the fire. Ashes left from fires are known to raise soil pH and be a source of calcium (references from Michigan State and University of Wisconsin-Madison). I’m not sure if fire enhances germination for this species as it does others, but I’m left wondering could it be that the ash generated after a fire burns through helps create conditions ripe for these plants to have a sudden growth explosion if they are not already growing in a calcareous soil? I’m already mentally thinking of the next experiment to set up!

But, for now, I’m delighted to have found an obscure native with such horticulture potential. Clasping jewelflower has become a gem in the crown of my spring garden, and now that I know how to successfully grow it, I look forward to being bedazzled by its reappearance every spring.

Solstice Seedlings

We are a a little over a week away from the winter solstice. The year has wrung about as much light out of the day as it can, and we have mere minutes left to lose until we hit the shortest day of 2022.

It’s in this solstice season that I start planning in earnest for next year. With the semester over, the growing season ended, and the new year on the horizon I have time to consider the goals and projects I want to move forward in the coming year.

The plants in my garden are preparing for next year, especially those whose growth culminates in spring. Even though March is months away, amongst the duff there are hints of the next growing season starting to appear. Every day harnessing the sun counts in the march toward warmer weather for making sugars that will become more blades and blooms.

I’ve spied the lobed foliage of Delphinium carolinianum (prairie larkspur) and Viola pedata (birds-foot violet) in the garden. The maroon leaves of Claytonia virginica (spring beauty) no longer hide amongst the tawny, frosted turf. I even found two with open flowers in our backyard this week. The little toothpick leaves of Phlox pilosa (prairie phlox) are emerging. And, the first of my perennial sowings from this year are germinating.  

Late last spring, I sowed Marshallia caespitosa (Barbara’s buttons) and Callirhoe alcaeoides (white poppy mallow) from seed collected in my garden.  I love both for their white flowers and desired more as they are good fillers for spring color. Callirhoe has this ability to thread itself through the matrix of foliage, and looking down on a Marshallia is like looking up at a galaxy. Both go dormant in my garden soon after they flower and set seed.

I decided instead of letting the progeny sit in storage in the fridge, I would promptly sow them and put them on my small nursery pad where they would receive occasional irrigation over the summer. Often with the first time sowing a batch of seed, I will sprinkle them on potting substrate in a gallon pot, trust mother nature, and watch and learn for next time. Both seem quite happy with this approach thus far.

Marshallia caespitosa

Callirhoe alcaeoides

Marshallia caespitosa seedlings

Callirhoe alcaeoides seedlings

Even though they got water all summer long, their emergence coincided with the return of cooler weather this autumn. Like many native perennial seeds, the delay makes sense to wait and start growth when conditions are more appropriate. The Callirhoe germinated fast while the Marshallia were more staggered.

Towards spring I’ll tease them apart and pot on into trays to allow each plant to have space to grow.  And, then once they’ve bulked up a bit, I’ll welcome these plants into the garden.

I suppose in retrospect my planning for 2023 started earlier in the year than just here at the end. Every seed I sowed in anticipation of having more plants for next year is hope and planning for greater things to come. Their appearance is yet another thing to celebrate in this solstice season.

Direct Sowing the Fall Garden

I’ve always thought of August as the start of a new year. While I suppose that living on a school calendar for some thirty years has engrained that into me, there’s more to that feeling than just the return of classes. Change is in the air. Summer is waning, and the days are palpably getting shorter. It’s time to begin planting the fall vegetable garden. As a young gardener who experimented around with season extension, I realized that the crops that I was sowing now would live on into the spring. And, that really to begin planning next year’s garden I had to begin in late summer. It was often time to start clearing out warm-season crops that were finishing up their production anyway. So, yes, it does have the feel of a new chapter beginning.

For us in east Texas, there’s about 90 days left until our first frost, so plantings are usually intense for a month trying to get everything started and in the ground to be able to overwinter. I typically start direct seeding in late August, so I thought I would share some techniques and cultivars that I’ll be direct sowing over the next few weeks.

Mustard and Collard greens

Even though mustard and collards are separate species, I’ve grouped them together because I start sowing these greens in late August. Growing mustard greens were a Tennessee tradition for our family. I hated them at first, but once I planted them in my own garden, I quickly gained a taste for this classic southern crop.

Collards came to me later in life. I first tasted collards at the Old Salem Tavern in Old Salem, NC. They tasted delicious flavored with bacon drippings and brown sugar, so delicious that I added them to my fall rotation.

I try to time my seed sowing with a good pop up summer thunderstorm or tropical storm moving through. But, those rain events are too often unreliable, so I set sprinklers up for a week to help seeds stay moist. To evenly disperse the seeds over the growing bed, I have mixed seed with sand and then broadcasted across the bed in a criss-cross pattern. But, planting them in rows allows for easier cultivation between the plants. So, the decision is yours based on the space you have available. In either case plants live all the way through the winter here in zone 8 with yellow cruciform blossoms emerging in the spring.

You’ll hear people say let the plants experience a frost for better flavor, and there is some truth to that. Plants increase the soluble sugar in their foliage when exposed to cold temperatures, which lowers the freezing point and acts as a natural antifreeze. After harvesting, I follow my Granny’s practice of tossing the midribs and soaking the remaining foliage in salt water to rid of any pests that might still be hiding amongst the leaves.

For mustard greens, I like the classic cultivars like ‘Tendergreen’ and ‘Florida Broadleaf’. There are also ornamental mustards. ‘Red Giant’ turns a beautiful violet, ‘Magma’ has chartreuse curls and is blushed rose, and ‘Tokyo Bekana’ has a golden hue to it.  

‘Magma’ mustard erupts in the fall with blushed leaves and chartreuse curls.

For collards, definitely check out The Heirloom Collards Project for old time varieties. ‘Alabama Blue’ has lovely steel blue foliage with purple petioles. ‘Variegated’ is another fun cultivar to grow because some individuals in the population will have green and white leaves.  

One year, I had ‘Alabama Blue’ collards seed into some tall grass. I could identify it by its purple petioles.

Peas

Peas were another crop that I hated until I grew it. The truth is I didn’t know what a good pea was. Most of the peas I had from the store were very mealy and had a horrible texture. But, one year on a whim, I tried some English peas from our Sprout garden, and I was blown away by the flavor. They were as sweet as candy.

Since then, I have dedicated a couple beds at home to growing peas both in the fall and the spring. I struggled with seed germination until I realized that my plants were succumbing to a fungal wilt. Since then I have only grown disease resistant varieties like ‘PLS 595’ and ‘PLS 141’.  I should add that I sow the seed densely. It seems counter-intuitive to space them close and not thin them, but the recommendation has worked thus far.

While I have used sapling stakes, I have appreciated the consistency with nylon support held by a T-post and electrical conduit frame. The conduit is fed through PVC T-joints that rest on top of posts. The vines are rambunctious growing towards the low sun; thus, I run cotton twine every foot or so to help encourage them to climb their trellis. They will tank with the first frost, but I rip them out and plant something cold tolerant like spinach in their wake.

Carrots

There is nothing like a fall grown carrot. Seed sown in early September will be ready around early November, but if you let them sit in the soil for another month or two, they will sweeten, again due to sugar acting as a natural antifreeze. That’s a trick I learned from Eliot Coleman, and while we don’t experience quite the extended cold they do further north, I still notice a different between fall and spring carrot flavor.

When sowing seed in late August/early September, moisture is crucial. The seeds have to be watered well every day for six days.  SIX DAYS. I cannot stress that enough in the south. To aid in moisture retention, I will often cover them with floating row cover and check daily for any sign of emergence on the seed. Note that as you sow later into fall, the time to harvest increases. Carrots sown in late November will be ready to harvest 3-to-4 months later.

My favorite cultivars include the orange ‘Napoli’, the crimson ‘Atomic Red’, the violet with orange center ‘Purple Haze’ (although seed has been hard to find of late), and the creme-amber-tangerine mix ‘Rainbow’.

Floating row cover held down by T-posts is an effective cover for reducing water evaporation from the soil to aid in carrot seed germination.

I’m super excited to welcome the fall garden back into production. Best of luck direct sowing seed for these crops this fall, and happy new year for all you cool-season gardening aficionados!

Don't Neglect This Muscari

Muscari neglectum is in full flower here at our homestead.  In my search for naturalizing early spring geophytes for east Texas, I heard this species would grow well for us.  I had seen yards full of it in the hill country further west in the state.  I’ve killed other grape hyacinths like Muscari armeniacum.  They’ll last for a season or two, but eventually fade.

However, this species, well, the epithet gives you an idea of the conditions this starch grape hyacinth tolerates. My plants came from an abandoned lot in town next to a makeshift parking lot. Nearby a discarded sofa and a chair sat, and being early spring, the grass and weeds hadn't grown up enough to hide the little purple bottles I spied passing by.

Late one afternoon, I decided to go dig some of the bulbs, and on a whim, I asked some students if they wanted to go help me rescue some of these geophytes.  I figured that with the numbers I saw we could even use some in our plantings on campus.

When we arrived, we discovered dense clumps of this heirloom flower. Some bulbs had found purchase under the turf but others were exposed and sitting on top of gravel and in full flower! They were surviving, dare I say even thriving in this ruderal soil. I assumed this location was where an old driveway of a house used to be. We dug a few clumps, and then made our way back to campus to parse out our new accessions.

A handful of an original clump from the abandoned lot. These Muscari are quite easy to divide; lift them and then rip apart into smaller groups.  It always amazes me how many bulbs are in one clump.

Once home, I planted them into a bed where I was already developing a cool-colored theme for spring. Planted nearby were the fuschia Glandularia canadensis and the soft blue Ipheion uniflorum. 

Muscari neglectum flowers against the backdrop of Glandularia canadensis. The burn you see on the Muscari and Gladiolus foliage is from the February freeze.

That was two years ago. Now, for much of March, these three play off each others colors and are some of the first plants to start flowering in my beds. I love watching bees of all kinds flit about the flowers.  One must get close to appreciate the finer details of the blooms, the little jugs with their white pencil-thin rims.  And, the color gradient of the raceme’s flowers is so rich as it changes from indigo below to a periwinkle top.  Once pollinated, the flowers become small tetrahedral seed capsules.

I have also planted them in our fledgling orchard on its shadier side where fewer Claytonia virginica grow.  They look like little purple rock candy suckers sticking out of the rough turf.  The darker slivers of the Muscari feel right in the dappled light, and unlike the fair-weather Claytonia virginica that only opens when the sun shines, these flowers are always on show. 

In the time since I planted my first bulbs I have watched each year as my plants multiply, both naturally and by division. I find myself pulling apart thick clumps anytime they aren’t in flower, which is easy since their bad-hair-day foliage has been up in the garden since early October. The wetter soils of winter welcome the splitting.

The leaves curl a bit, like a bad hair day

The little slivers of Muscari emerging in a bed amongst other perennials

But, I discovered something new about propagating this species last year.  Weeding one day I found a clump whose roots had been nibbled on by blasted gophers, and in pulling out what was left to reset in firm earth, I noticed that some of the bulbless leaves had roots on them!  I was amazed.  Eucomis is the only other geophyte that I know where more plants can be made via leaf cuttings, so this discovery was quite delightful.  They are both in the Asparagus family, so perhaps there is some family connection with this adaptation. I am happy to know yet another approach to making more of this great geophyte.

Adventitious roots on the bottom of Muscari leaves. Look closely and you’ll even see new bulbils.

Winter Sowings

Sowing perennial seed is one of my favorite tasks of winter.  There's so much anticipation wrapped up in this simple practice, even more so than sowing say lettuce or tomato seeds with their quick germination.  Perennial seed, both woody and herbaceous, may take weeks or months before the first hint of green is seen, so even in this waiting there is an air of mystery. My eyes hover over the trays as I search for life, and I find myself wondering if and when.

Many perennials have evolved to use the exposure to wet cold as an indicator for when they should emerge from dormancy and resume growth.  When I teach the concept of this physiological dormancy to students, I liken this period to an alarm clock.  Seeds have to get the appropriate amount of wet chilling time for the maximum number of seeds to germinate (or “wake up”).  Without this exposure, none or only a few may start growing (as far as the few goes, variation does exist within a population!).  This moist chilling results in physiological changes to the embryo that then allow the seed to overcome dormancy. You can hypothesize how this could be selected. Those that emerge early die in the cold. Those that bide their time awake to a glorious spring and can pass on their traits.

The staggered germination of Echinacea sanguinea. Note that there are a few larger ones with two or three true leaves that evidently didn’t need any chilling to enhance germination, but many seeds did and have only their pair of cotyledons. Don’t mind the wavy-leaf Streptanthus on the bottom or the couple of Penstemon tenuis that creeped into this block.

While this method of overcoming of dormancy occurs in nature, we horticulturists call the practice where we expose seeds to cold and moist conditions cold stratification (there is also warm stratification for some seeds, hence the addition the modifier).  Usually the seeds are placed in moistened sand, perlite, vermiculite, peat moss, or some blend of those; I've even used paper towels and coffee filters if they go into the fridge.  Now, mind you, all seeds don’t need this exposure.  Again, I recommend Norman Deno's wonderful online Seed Germination Theory and Practice to investigate the requirements. 

I've always wondered about the etymology of the word stratification. Strata means layers, not seed. Then, I read in Hartmann and Kester’s Plant Propagation: Principles and Practice how nurseries used to make layers of seed that were separated by moist substrate in outdoor pits. These “strata” were allowed to overwinter there.  One of the earliest historical writings about stratification is found in Sylva by John Evelyn in 1664.  I've shared his writing below of how he recommended stratifying, and to save myself from writing "[sic]" every other word, just note that spellings back then were a bit different. 

“Chuse your seed of that which is perfectly mature, ponderous and sound; commonly that which is easily shaken from the boughs, or gathered about November, immediately upon its spontaneous fall, or taken from the tops and summities of the fairest and soundest trees, is best, and does (for the most part) direct to the proper season of interring, according to institution.

Nature herself who all created first,
Invented sowing, and the wild plants nurs’t:
When mast and berries from the trees did drop,
Succeeded under by a numerous crop.

Yet this is to be consider’d, that if the place you sow in be too cold for an autumnal semination, your acorns, mast, and other seeds may be prepared for the vernal by being barrel’d, or potted up in moist sand, or earth stratum super stratum during the winter; ... Chuse a fit piece of ground, and with boards (if it have not that position of it self) design it three foot high; lay the first foot in fine earth, another of seeds, acorns, mast, keys, nuts, haws, holly-berries, &c. promiscuously, or separate, with (now and then) a little mould sprinkled amongst them: The third foot wholly earth: Of these preparatory magazines make as many, and as much larger ones as will serve your turn, continuing it from time to time as your store is brought in. The same for ruder handlings, may you also do by burying your seeds in dry sand, or pulveriz’d earth, barrelling them (as I said) in tubs, or laid in heaps in some deep cellar where the rigour of the winter may least prejudice them; and I have fill’d old hampers, bee-hives, and boxes with them, and found the like advantage, which is to have them ready for your seminary, as before hath been shew’d, and exceedingly prevent the season. ”

Don't you just love the poem in the middle there?

Of course our technique has improved since the 1600's.  In the past I have put the seeds in the fridge, and I have colleagues who also use this cooler method.  But, I like to take advantage of natural winter chilling to germinate seeds.  It is so much easier than bagging seeds up, putting them in the fridge, and then remembering to sow them later on.  Why artificially create what nature already offers?  Also, there is some evidence that the diurnal changes in temperature may positively promote germination. 

Last winter, I filled the cold frame with 4 inches of growing substrate and sowed several different species directly into that media.  We were traveling for the holidays, and I was worried about the seeds drying out too much in individual cells while we were gone. This method worked well.  I got good germination on most species, but sowing en masse made it difficult to separate them when planting up later on. 

The cold frame last winter. Old, used labels that were headed to the trash became block edges for different species.

This year, I sowed the seeds into trays to make it easier on me.  We didn't travel over the holidays, and I was able to more closely monitor their moisture levels.  Because I knew I would run out of room in my cold frame this year, I built a small low tunnel frame where I can cover a 4 × 8 ft area with floating row cover supported by the same hoops I used to cover my vegetable beds.  The floating row cover provides just enough protection to keep the frost off. 

In my rush to get the seeds sown and because a few of them of them still have fluff or chaff on them, I don't fret much about trying to get one seed per hole.  I can always transplant or move seedlings around later in their cells.  I will note that I flame some seed like Liatris, Andropogon, and Asclepias in a bucket to get the fluff off the seed. 

I am fascinated by seeing the differences in germination time, even for some species in the same family.  For example, Penstemon tenuis germinated fairly quickly within a week while Penstemon digitalis took a month from sowing to start showing cotyledons. 

Penstemon digitalis takes longer to germinate than Penstemon tenuis (not pictured).

Winter is a good time to clean out the fridge for seeds and go through old boxes.  I had hoped to be done by now with my winter perennial sowing, but I keep finding more species that I saved earlier this year to sow now.  For most of the country you should still have a little time to get seed that need stratifying sown outdoors or just use the fridge method I mentioned earlier. Either way is sure to result in more plants this year for your garden.

Ipomopsis rubra was another fast germinating species. I transplanted them out shortly after this photo.

Amsonia hubrichtii emerge from their cigar-shaped seed.

The thread-like cotyledons of Lilium formosanum

Carex cherokeensis, Cherokee sedge

Ever since I learned of the concept of matrix species from Noel Kingsbury and Piet Oudolf’s book Planting: A New Perspective I have searched for and evaluated good ground covering plants for the southeast.  One that I have enjoyed getting to know better is Carex cherokeensis or Cherokee sedge.  

A snapshot of Carex cherokeensis in our modest grass and Carex trial at the Plantery at Stephen F. Austin State University.

I first learned about this species when the Plantery conducted an informal trial of grasses and sedges at SFASU thanks to the help from the fine folks at Hoffman Nursery in Rougemont, NC.  Carex cherokeensis showed us it was a stalwart for east Texas.  In my naiveté, I didn’t realize it was native to our area until I found it growing along a roadside west of town.  And, then imagine my delight when I found three plants in a wet spot of my yard this past winter.  I chuckle when I think that we ordered plants from halfway across the country, and they were growing in my own backyard (literally!)

While the inflorescences are not very showy, closer inspection reveals there is a beauty to the dainty seedheads of Carex cherokeensis.

So, why do I like this living mulch?  For a variety of reasons.  The verdant foliage livens a dappled understory, and it tolerates full sun conditions like a champ with little burning.  It was also tolerate most soils save for those with heavy sand. From my encounters with Cherokee sedge in the wild, I noticed that it tends to occur as small, almost solo crowns. However, plant it in a bed, and it will form a nice cespitose clump.  It may sit there for a year, but be patient, and let it get established.  The inflorescences are not too conspicuous. They resemble inverted wheat ears and hang like thin beaded earrings above the foliage.  We do remove the whole peduncle after the seed have dropped. 

A mass of Carex cherokeensis

The students used this Carex in our food prairies in the Sprout garden, and we have slowly watched over the past three years as it has colonized open spaces with rhizome and seed.  We mow it once a year in early January when we cut back our plantings to prepare for spring bulbs to emerge. It divides well, too.  I regularly have students divide a few plants early in the semester for a primer on division and then use it in later exercises on grading propagule sizes.   

This past year, I tried propagating it from seed at home.  I collected seed from my Texas germplasm last spring and stratified it for a couple months.  I sowed it in a flat outdoors last fall and waited.  After a few weeks, I noticed a couple of green slivers popping up out of the soil but only a few.  At first I wondered what I did wrong and why more weren’t germinating.  Later, I saw that the tray had more, and eventually I came to realize that it seemed as if a few new ones were germinating each month.  

Grading Carex cherokeensis seedlings at my house. These were large enough to pot on.

The rest were allowed to remain in the tray to bulk up. Again, notice how some are barely up while others have some size to them.

I’m not sure if it’s an effect of my sowing efforts or the plant’s staggered germination biology.  Either way, I’m happy to have about 50 more plants to add to my landscape of this great Carex species.  

Hey, Sarracenia, I like your style

I learned how Sarracenia pollinate this week!  Some of my pitcher plants are flowering, and I text Jevon, one of my students who is keen on carnivorous plants, to help me understand what to do since I wanted to make some crosses in my collection.  He told me that the cap that shields the pollen is actually a modified style and has stigmas on the tips.  Bees enter the flower through entrances on the style platform where pollen drops, and before they leave they would brush against one of the five stigma, hopefully carrying pollen from a previous individual.  Boom, cross pollination occurs.  It’s a brilliant approach to help prevent self pollination.  I think the stigmas curled up and away from the pollen-loaded stamen helps even more.  

The appendage I’m grasping is part of the style on this Sarracenia alata. The white spot near my thumb is the stigma where I’ve just placed some pollen from Sarracenia × areolata. There are five stigmas, and I applied pollen to all five in hopes of getting seed set.

I was blown away.  In all this I realized I had never seen a pitcher plant in flower before with the draped petals, and thus never really had a chance to process the floral mechanisms.  It’s always nice as a professor when the student becomes the teacher.  

Sowing Perennial Seeds

With the arrival of February and warmer temperatures, I've been sowing seeds in earnest this week, perennials in particular.  Seeds purchased or collected last year have the chance to sprout.  My goal is to get them started for easy propagation in years to come for planting prairies here at the house.  

Two species that I've had stratifying—a cool moist period to enhance germination in some species—in the refrigerator are Asclepias tuberosa 'Wild Orange' and Echinacea sanguinea.  I've checked on them weekly in the little baggies by opening the moist paper towels and inspecting them.  It's a nice way to also introduce some fresh air in the sealed vessels since seeds need oxygen for germination.  For the Asclepias, I noticed swelling in the seeds and some rupturing of the seed coat, a clear indication they were ready for planting.  The Echinacea seed held onto their dingy off-white color while the other detritus from the seed head turned black.  

Plump Asclepias tuberosa seeds. Seed the tinge of light yellow? The seed coat has ruptured on one near the center.

Echinacea sanguinea seed were mixed in with parts of the flower head. I decided to stratify them together and pull the seeds out when sowing.

These made their way into seed trays earlier this week.  With the Asclepias I was sure to sow the seeds in a tray deep enough (approximately 5–6 inches) to allow their roots to grow down.  Allen Bush shared with me that shallow trays can cause their demise because the root doesn't have enough room to grow down.  

Along with the seeds that have been chilling in the fridge, I also scarified some seed this week and allowed them to soak for a couple of nights to prep for planting.  Scarification damages the seed coat and allows water to enter.

Last August, I collected some Baptisia sphaerocarpa seed from a location I saw it blooming several years prior.  Fingernail clippers make quick work breaking the seed coat on a few seeds.  

A few roots began to appear on Baptisia sphaerocarpa.

Another species that I scarified was Amsonia tabernaemontana.  The seed came from my dad.  Years ago, I found an Amsonia blooming on the roadside near home.  The fear that it would succumb to the mower or herbicide like I had witnessed happen to many other plants inspired me to relocate the clump to our yard.  It settled in nicely and started producing seed.  A year or two ago, I asked my dad to collect any fruit he saw, and that Christmas I returned home to find the baggie on the windowsill.  Now that I have a house of my own, I felt it time to try growing the northern provenance here.  The germination requirements were unknown to me; however, from a quick google search, I discovered researchers at UGA demonstrated that clipping the end of the seed would allow moisture in to kickstart the germination process.  

Amsonia tabernaemontana seedlings emerged from an intriguing cigar-shaped seed. With the embryos popping out, they look like sea tube worms.

Today the seeds are in the garage instead of their cold frame.  The forecast showed below freezing last night, and I didn't want to take any chances since I've worked hard to get them all started.  Here’s to hoping they all germinate!