Cold house harvests

I continue to be amazed at how well the lettuce, arugula, spinach, kale, and mesclun mix has done in our 'cold' teaching greenhouse. 

We haven't run any heat all winter (and it's been exceptionally cold), but the warmth created through the poly covering, along with the stored heat of the barrels of water seem to provide enough heat for these greens to thrive. 

harvested lettuce mix

There are fungus gnats (a kid today said, hey, they're insects in the pots-it's organic, I replied -- it's OK), which are to be expected in warmer, rich soil, but I guess I need to figure out how to reduce their numbers.

I've been thrilled with this experiment (I provided seeds and bags of organic soil mix).  And we've had growth, not just winter harvest, thanks to our longer days at this latitude.

A long fall season

After a mild frost (30-32°F) last weekend, we've had lovely warm days (highs near 70° F) with lows in the 40's.  Tender annuals and perennials were zapped, of course, but hardier plants, whether ornamental or vegetable, sailed through.

In our (SE US) climate, it's always variable, and with a mix of plants from around the world in our gardens (vegetables included),  it's hard to predict HOW the impact of oncoming cold weather will affect our individual gardens.

There's always the site to consider, and exposure, in addition to how frost affects our plants (whether edible or ornamental).

We're doing an experiment in our unheated education (Sprouting Wings) greenhouse this winter (I've posted about this previously).

It'll be interesting see if we can 'grow' greens in the winter, beyond simply holding them for harvest.

Winter greens and other winter vegetables

We're doing an winter vegetable gardening experiment in our unheated education hoop house (it used to be a 'greenhouse').

Propane costs ran up to $500/month to heat the house (and after losing all of the tropical plants after an severe freeze, without heat, a couple of years ago), it's quite appealing to run the house as a demonstration 'cold house'.

In our Piedmont South Carolina winter, we only have a few weeks with less than 10 hours of sunlight a day.  That's plenty to support winter greens to harvest, and probably to grow  -- I'm thinking we'll be able to do successive lettuce mix plantings as well as grow hardy and semi-hardy vegetables in containers.  (This house has a gravel surface so isn't conducive to ground sowing.)

West Dean, UK cold frame

We sowed various mixes of greens today, and will be doing more in the coming weeks.  There may be enough light for greens to grow through mid-December and take a rest, and then resume growing, but temperatures will be important, too.

We've got a bank of black plastic drums (recycled soft-drink syrup containers) filled with water that will be serving as a reservoir of heat, and we can always add a second layer of frost-protection with floating row covers.

If Elliot Coleman and Barbara Damrosch can grow greens in coastal Maine in unheated houses, surely we can manage to extend our growing beyond kale and collards in the Southeastern U.S. (They're tasty, of course, but lettuce, spinach, and arugula are great additions to winter salads.)

Winter vegetables

In the Southeastern U.S., we're blessed with plenty of winter sunshine (at least compared to Northern and Central Europe and Northern Asia) -- I need to check corresponding parallels in Asia, to be sure, actually.

And our winter temperatures aren't so bad either, being much more moderate than the Northeastern U.S. We often experience relatively mild winters, although it's variable, and more recently, even more so.

In the mountains of N.C., we're Zone 6, but have only had a light frost so far, which even romaine lettuce of unknown hardiness (transplants from a big box store) sailed through.  With predictions of 28°F for next weekend,  I harvested all of the outside (lettuce) leaves this afternoon, and chard leaves of any decent size, and the arugula in that category, too, before heading down the 'hill' tomorrow.  I'm sure that the frost/freeze might not amount to much and the raised beds are plenty buffered by their stone walls, but I'd rather enjoy eating the greens than clean up the frost-bitten remnants on a later trip!

The young mesclun mix, kale, and mustard seedlings are on their own.  I'll be delighted to harvest any of them.  The parsley is looking great, too, so I'll probably cut quite a bit tomorrow morning, too.

At home in the Piedmont (Zone 7b), I've planted several beds of garlic, but need to tuck in a couple of more beds.  And I have flats of kale, arugula, and other greens to tend.

I'm planning for a winter vegetable garden experiment in one of our unheated houses at the Garden where I work.  Doesn't it seem like winter greens are a no-brainer?

Check this book out (The Winter Harvest Handbook by Elliot Coleman).  It's a fabulous guide (and inspiration) to what more of us should be doing.