Reflections on Season Extension

I love winter.  Yes, it may seem odd to hear this coming from a horticulturist as with it comes the end of the main growing season, but there is something about the cold, the starkness, and the frost (and potential for snow!!!) that enchants me about this time of year.  In Tennessee where I grew up, this shift in seasons was a bit harsher than it is here in Texas.  But, winter can still have its moments here in zone 8b, too. A few years ago, we experienced 11F, 12F, and 14F three nights in a row.

Even though much of our plant activities are on pause, I like to cheat the these colder months out of a little more with season extension. Extending the growing season for cool season crops relies on two principles, simple, unheated structures + cool-season crops. 

My first forays were simple straw bale cold frames that I saw in gardening books.  I didn't have the means to get glass panes made, so I would get old windows from my family and neighbors nearby to use as a covering.  The straw was good insulation.  It was in these structures that I started my tomatoes and other vegetable transplants. 

One of my first cold frames.  You may be wondering about the hog wire.  That was used to keep the dogs out.

One of my first cold frames. You may be wondering about the hog wire. That was used to keep the dogs out.

Eliot Coleman really helped to open my eyes on season extension with his book The New Organic Grower.  In 2014 I built my first ever plastic covered low tunnel in my garden.  I didn't know much about what I was doing.  I used PVC pipe and painters plastic from the hardware store. Within a couple of months, the cover split right down the middle.  But, I was delighted to see that what I was growing in this structure actually worked and that you could continue gardening through the winter in Tennessee.

My first two low tunnels in my garden in 2004.

My first two low tunnels in my garden in 2004.

A rare eight-inch snow event showed me just how sturdy these structures were.

A rare eight-inch snow event showed me just how sturdy these structures were.

I buried the edges before I realized that sand bags were a thing. It was hard to take the plastic off, and I got down in them and crawled around. It's fun thinking back now about how I got under those covers and scurried around working in my covered beds. 

Fun as it was, the strain on my neck made me want to build something larger.  So, I experimented around next with an A-frame made out of electrical pipe from the local hardware store.  Armed also with more weather resistant plastic, this structure could be walked into, and I did not have to worry about the cover degrading.  I learned about wiggle wire, this simple wire-channel combo that helped to hold plastic down, and I used it on the A-frame end for quick access to my plants.

My A-frame in 2006 after another snowfall.

My A-frame in 2006 after another snowfall.

Inside, mizuna, beets, and spinach are happily growing in the cold.

Inside, mizuna, beets, and spinach are happily growing in the cold.

As my love for season extension grew, I convinced my parents to let me build a small 16 x 24 hoop house at our home in 2008.  Just like the other structures, this greenhouse was unheated and relied on natural heating from the sun. But, it allowed for more experimentation. Inside it was a cold frame; putting protection within protection helped to increase the season extension effect.

Yay!  My first greenhouse!!!  This snow event was a rare sight in March.  You can see the Narcissus foliage on the side poking through the white.

Yay! My first greenhouse!!! This snow event was a rare sight in March. You can see the Narcissus foliage on the side poking through the white.

Inside the hoop house, spinach, cabbage, beets, carrots, and more are visible.

Inside the hoop house, spinach, cabbage, beets, carrots, and more are visible.

Spinach, onions, kale (left, front to back), corn salad, and mache (right, front to back) all survived multiple nights of below freezing temperatures during the 2007-2008 winter.

Spinach, onions, kale (left, front to back), corn salad, and mache (right, front to back) all survived multiple nights of below freezing temperatures during the 2007-2008 winter.

I decided to track night low temperatures using thermometers over two weeks in January 2008 outside the hoop house, in the hoop house, and under cover, just like the young scientist I was. You can really see the effect of this cold frame in the unheated hoop house in the figure below. While the outdoor low and hoop house low were close to each other most nights, the cold frame temperature registered consistently higher than both of them. One other thing that I’d like to point out is that even with temperatures as low as 8F, crops like spinach still were able to survive in the hoop house with one layer of cover.

The outdoor, hoop house, and cold frame low give a sense of just how cold these plants can tolerate.

The outdoor, hoop house, and cold frame low give a sense of just how cold these plants can tolerate.

However, after winter that I left for grad school, and I had to put my season extension experiments on pause while I lived in an apartment. Now that I have a garden again, I’m back to covering crops during the winter to see just how much I can squeeze out of the growing season. I’ll add that in the six year hiatus the technology has advanced so much. Now with pipe benders you can make hoops out of electrical conduit pipe for around $3 a pipe, and then cover these arcs with floating row cover that lasts for a few seasons if you treat it right.  These permanent hoops are great.  Not only do I use them in the winter, but I also cover squash in the summer to prevent squash vine borer.

My latest iteration on season extension uses bent electrical conduit and floating row cover.

My latest iteration on season extension uses bent electrical conduit and floating row cover.

To me, it’s fun to be able to go out in the middle of winter and harvest a salad grown right in my backyard. It is so simple I believe that everyone can do it. So, experiment around with season extension to see just how much can be grown by pushing the limits beyond frost. You’ll be pleasantly surprised

Christmas Cheer at Williamsburg

This holiday season I’d like to take you back in time to 2010… and the 18th century. Each winter when living in Raleigh, I liked to take a weekend trip to see something Christmasy on the east coast before heading home for the holidays. Ten years ago almost to the day, I planned a Sunday get away to see a rustic, foraged Christmas at Colonial Williamsburg in Virginia. In an age before the crafting of Pinterest and Instagram became more prevalent in our lives, it was so inspiring to see simple, everyday plant parts used in such clever ways to bring a bit of joy and delight to this darker season. And, I return to these photographs each year to see ideas and inspiration I got from my visit. So, enjoy the below photos that I took that dreary day walking the old-timey streets of this historic town.

As you’ll see in these photos, fruits played center stage in many winter arrangements.  Here, pomegranates, lemons, and apples are set with dried artichokes and coniferous cones.

As you’ll see in these photos, fruits played center stage in many winter arrangements. Here, pomegranates, lemons, and apples are set with dried artichokes and coniferous cones.

The acid green osage orange plays well here with pineapples and apples. Sumac seedheads, wax myrtle fruit,  and catalpa pods are up top.

The acid green osage orange plays well here with pineapples and apples. Sumac seedheads, wax myrtle fruit, and catalpa pods are up top.

Here the halls are decked with apples and deciduous holly.

Here the halls are decked with apples and deciduous holly.

Some of the wreaths and designs were a bit less traditional.  I loved this banner above the door.

Some of the wreaths and designs were a bit less traditional. I loved this banner above the door.

 
Magnolia leaves were used in many wreaths for their evergreen nature, and I loved how they incorporated clam shells and dried yarrow heads to create a faux magnolia flower in this wreath.

Magnolia leaves were used in many wreaths for their evergreen nature, and I loved how they incorporated clam shells and dried yarrow heads to create a faux magnolia flower in this wreath.

 
Many decorations were primarily made from dried goods like the chaste tree branches and sunflowers here.

Many decorations were primarily made from dried goods like the chaste tree branches and sunflowers here.

A bundle of wheat makes a striking door accessory.

A bundle of wheat makes a striking door accessory.

Here dried plant parts make up the red, white, and blue.

Here dried plant parts make up the red, white, and blue.

The peels of dried oranges were used to add some zest to this arrangement.

The peels of dried oranges were used to add some zest to this arrangement.

And, here we see slightly dried oranges used as pendulous ornaments with pomegranates and acorns.

And, here we see slightly dried oranges used as pendulous ornaments with pomegranates and acorns.

 
Even dried oak leaves were incorporated into some wreaths.

Even dried oak leaves were incorporated into some wreaths.

 
This wreath was my favorite of the day.  Not only did I love the use of cotton to simulate smoke, but the color echo of door and wreath and the asymmetry of the cotton with the variegated holly was spot on.

This wreath was my favorite of the day. Not only did I love the use of cotton to simulate smoke, but the color echo of door and wreath and the asymmetry of the cotton with the variegated holly was spot on.

In the south I worry about fruit having holes punctured in them for wreaths.  This design solved that problem by wrapping the fruit with colorful fabric.

In the south I worry about fruit having holes punctured in them for wreaths. This design solved that problem by wrapping the fruit with colorful fabric.

Occasionally, I saw doors with blue ribbons that were awarded for the most creative designs.  To make the designs in the spirit of the place, there were rules like one could only use materials that colonists would have available to them back in the …

Occasionally, I saw doors with blue ribbons that were awarded for the most creative designs. To make the designs in the spirit of the place, there were rules like one could only use materials that colonists would have available to them back in the day. So, here you see a fish made out of gingerbread.

 
This design was another blue ribbon winner. A gingerbread queen bee watched over her hive and honey.

This design was another blue ribbon winner. A gingerbread queen bee watched over her hive and honey.

 
 
And, I was delighted to see a Star of David with adorning dreidels.

And, I was delighted to see a Star of David with adorning dreidels.

 
And, I can’t leave showing you photos of horticulture in Williamsburg without a picture of the vegetable garden and the clever techniques displayed for how early gardeners could have extended the harvest!  Here you see cut branches, cloches, mulches…

And, I can’t leave showing you photos of horticulture in Williamsburg without a picture of the vegetable garden and the clever techniques displayed for how early gardeners could have extended the harvest! Here you see cut branches, cloches, mulches, and paper frames used to protect early crops. The paper frames were the most interesting to me. From the gardener Wesley Greene, I learned that day they were made from cotton and coated in linseed oil. These designs date back to the 1770’s. So, if colonists can extend the season, so can we.

Feather Bluestem against a Golden Sunset

Driving to and from town I’ve admired a big patch of Andropogon ternarius in late season splendor right up the road.  It's pretty easy to spot once it comes into flower.  The inflorescences have this sheen to them, almost like long silver paintbrush bristles.  A month or so later, the bristles fray as the seed ripen, and the plant forms a pair of feather-like infructescences.  The seed heads glow a white blush no matter how the sun shines on them. Most people call this species split-beard bluestem, but I’m partial to the common name feather bluestem for its twin inflorescences that resemble bird plumage.

Before metamorphosing into the feathery seed heads, the flowers of Andropogon ternarius look like silvery paintbrush bristles.

Before metamorphosing into the feathery seed heads, the flowers of Andropogon ternarius look like silvery paintbrush bristles.

I stopped the other evening as the sun approached the horizon to take some photographs of this colony of feather bluestem.  Just like the rest of the landscape, the grasses glowed warm in the waning light of a cool evening. 

Andropogon ternarius en masse. I wonder if the purpletop grass behind it to the right is a bit jealous just how good the feather bluestem looks?

Andropogon ternarius en masse. I wonder if the purpletop grass behind it to the right is a bit jealous just how good the feather bluestem looks?

The culm colors were variable, but some were a vibrant cinnabar.  I pondered if the coloration I saw was more an effect of genetics or the stresses of the site.  I could see drought or low phosphorus bringing out these red colors more. 

 
The cinnabar-colored culms warm the heart on a cool evening while photographing Andropogon ternarius

The cinnabar-colored culms warm the heart on a cool evening while photographing Andropogon ternarius

 

While the primary role of the hairs, technically trichomes, is to help the seeds disperse in a stiff breeze, I’m amazed at how well they capture light and diffuse it. From a distance they look like lines of white dots, a natural pointillism if you will.  However, up close when I stood behind the plants and squatted down to see the sun through them, I noticed an interesting phenomenon with how the waning light interacted with the seed hairs.  The light formed concentric circles around the sun as each bristle became a mini light reflector. 

 
The light orbits the sun in the seedheads of Andropogon ternarius

The light orbits the sun in the seedheads of Andropogon ternarius

 

In my photographing the plants against the light, a Carolina Wren popped up to the barbed wire fence and sang its cheeseburger–cheeseburger-cheeseburger song.  It pranced a little bit, perhaps curious who was disturbing its niche, before flying off home. 

The bird of a feather bluestem.  I wonder what this Carolina Wren thinks of Andropogon ternarius?

The bird of a feather bluestem. I wonder what this Carolina Wren thinks of Andropogon ternarius?

I'm so glad I stopped to enjoy the beauty of these feather bluestem late that Wednesday afternoon. Two days later roadside mowers came through and cut the whole patch to the ground.  It is sad the feather bluestem won't be there for me to enjoy it all winter as I drive to town.  But, in their clearing the roadsides, they just propagated more of the plant by dispersing those seed for me to enjoy in years to come.

I, too, will be propagating this plant via seed. You see, having lived here for four years, I was anticipating their autumn cutting, and I collected some seed that evening in the twilight. I’m just glad they waited long enough for me to enjoy this final show and let the seed ripen. And, soon I won't have to just enjoy the patch down the road.  I'll have my own feather bluestem here glistening in the setting sun for my enjoyment and the Carolina Wren’s. 

Thanksgiving Snowdrops

Thanksgiving makes me think of snowdrops because the weekend after the holiday my friends and I would travel to Hillsborough, NC to see one of the rare forms of Galanthus at Montrose, a historic garden tended by Nancy Godwin.  While most snowdrops typically start flowering later in winter, these autumn snowdrops (Galanthus elwesii var. monostictus) can be in full flower sometime around Thanksgiving, a full month or two earlier than other Galanthus

Closeup of autumn snowdrops.  I love how the petals of the inner perianth have the green upside down heart on them.

Closeup of autumn snowdrops. I love how the petals of the inner perianth have the green upside down heart on them.

My friends Alice, Keith, and Kim traveled with me on my last trek to see snowdrops while living in Raleigh in 2013.  The weather that Sunday afternoon was lovely.  Nancy described the mid-fifties with a sunny, bluebird sky as a “miracle,” and with it and good conditions over the past few weeks, the snowdrops were looking superb.  

Nancy stops our group briefly at Montrose to give us a teaser of the tour.

Nancy stops our group briefly at Montrose to give us a teaser of the tour.

We were some of the earliest of the sixty or so visitors to descend on the garden for the snowdrop walk, and our prompt arrival ensured us Nancy as our head guide.

As we approach the back of the garden, excitement began to build as THOUSANDS of snowdrops come into view.

GASP!  It almost looks like a dusting of snow in places, doesn’t it?

GASP!  It almost looks like a dusting of snow in places, doesn’t it?

While Galanthus can be appreciated while standing, the diminutive size of snowdrops beckons gardeners to humble themselves upon the earth to appreciate their beauty, much like we see Kim doing here with her camera.  

While Galanthus can be appreciated while standing, the diminutive size of snowdrops beckons gardeners to humble themselves upon the earth to appreciate their beauty, much like we see Kim doing here with her camera.  

Nancy was keen to lead us along the path to highlight her favorite views, which finally crescendoed into us seeing the plants with the sunlight to our backs and the snowdrops in our front, a perfect angle for the light to play off the flowers well.  She tells us that in 1987 she acquired 12 bulbs from a local seed store for less than a dollar, and by happenstance they were this rare variety.  She started the mass planting seen above in November 2002 and has helped it enlarge via division.  She made the comment that she’s glad she bought the bulbs.  We are, too. 

The snowdrops don’t stop here. We are then lead through the woods where a large, long drift—perhaps a 1/10 of a mile long—has been planted, and along the path Nancy points out a few Cyclamen coum that have just started flowering.  However, most need not be in bloom to be attractive as the leaves on some cyclamen appear as if ornately arrayed shields of green, gray, and white.

 
The long drift pulls you into the woods to see just how far it goes.

The long drift pulls you into the woods to see just how far it goes.

 
Some of the diversity in Cyclamen foliage along the path through the woods.  The leaves look like little shields scattered upon the forest floor.

Some of the diversity in Cyclamen foliage along the path through the woods.  The leaves look like little shields scattered upon the forest floor.

For me, snowdrops mark a turning point in the year, evidence that even though winter is here, spring approaches.  Many gardeners are fascinated by these winter bloomers to the point of obsession.  I’m not there yet, but I hold with Christopher Lloyd as he wrote in Garden Flowers, “We all of us need more snowdrops in our gardens”, and “[s]nowdrops are graceful, welcoming, sheer delight, and I fail to see how one could have too many of them.” If you’ve never seen them before, the pictures included here will certainly help.  When visuals are absent, I describe the plants as diminutive street lights, the white perianth dangling from six-inch scapes, much like a lantern might have hung from posts in days of old.

Galanthus flowers hang like lanterns on hooks.  While they produce no foot candles, they certainly brighten winter.

Galanthus flowers hang like lanterns on hooks. While they produce no foot candles, they certainly brighten winter.

The lantern comment brings to mind a story I once heard in a sermon.  Robert Louis Stevenson as a child was sickly.  One evening, the nurse came to check on him and found him sitting near the window watching the lamplighter.  The nurse hastened him to get back in bed, but he was mesmerized by the lamplighter who he said was “poking holes in the darkness.” For me that’s what snowdrops do.  They poke holes in the darkness of winter, and having some that bloom early like these autumn snowdrops and some that bloom late can make sure that all of winter is a little brighter in our gardens.