Your Living Refrigerator: Low Tunnels

By  |  4 Comments


For many people, Labor Day weekend heralds the end of the gardening season. The garden is cleaned up, and a cover crop is planted (hopefully). For me, Labor Day weekend is when I begin preparing my family’s winter meals in earnest.

I’ve done my fair share of freezing and canning through the summer, for sure. And I just finished curing 223 lbs of winter squash for storing in the crawlspace under our house. Then there are all of the sweet potatoes and cowpeas that we harvested. What else could we possibly need?

FRESH produce! Salads. Asian greens for venison stir-fries. Carrots for winter stews. Swiss chard!

I guess I could buy those things at the grocery store, but I’d rather not. Quality is definitely an issue; it’s not uncommon in my town for vegetables to sit for weeks on the shelves. And I’m skeptical of grocery store produce from a food safety perspective as well. Back in the good ole days, bugs like Escherichia coliSalmonella, and Listeria were only associated with raw hamburger, chicken, or milk – now they are showing up on our salads, tomatoes, and cantaloupe.

What’s a mother to do? Even if you did grow your carrots, beets, chard, bok choy, kohlrabi, and salad mix, there is no way you could store it in your refrigerator all winter long!

So make a Living Refrigerator instead.

I’m talking about “low tunnels,” a twist on the cold frame concept that is ideal for small urban gardens. Cold frames, typically made out of a wood frame with a transparent glass or plastic cover, are bulky and difficult to store when no longer needed. Low tunnels, made out of metal or PVC hoops with fabric and/or clear plastic sheeting, take up very little storage space when not in use.

The Agribon cover shields plants from freezing temperatures and the weight of snow.


Why do I call them Living Refrigerators? Actually, I never have before, but the thought occurred to me yesterday as the girls and I planted seeds in the newest low tunnel bed. Although low tunnels are often used to protect plants from frost as they get established in the early spring, you can also use them in reverse – for protecting mature plants in the winter months, allowing you to extend the harvest period. Many cold-hardy plants can tolerate freezing temperatures, but they still grow SLOWLY when it’s cold – you’re essentially offering them some extra winter protection until you harvest.

Timing is important to the Living Refrigerator’s success. Plant crops too early, and your plants enter the winter too mature; they may become tough, or begin to bolt. Plant crops too late, and they don’t get enough of a head start on winter; then they’re only good as micro greens, and that won’t get your family very far.

In the Living Refrigerator that I planted Labor Day weekend, I have:

  • Carrots (4 varieties, including white)
  • Beets (4 varieties, including golden)
  • Swiss chard
  • Lolla Bionda lettuce
  • Cimarron Romaine
  • Kohlrabi (white and purple varieties)
  • Asian greens (mizuna, pak choy, tatsoi, michihili cabbage, joi choi, japanese giant mustard, etc)
  • Spinach
  • Rutabaga
  • Turnips

All in a 5 x 40 ft bed… just half a decimal.

Early Purple Vienna Kohlrabi, Lolla Bionda lettuce, De Meaux Endive

Cimarron Romaine, with Swiss chard and beets in the background


I’m a little anxious about this bed, though. I planted with the first frost date in mind – October 15th. Then our first frost date was delayed by two weeks. Now we’re having daytime temperatures in the 60s and 70s. With this unseasonably warm weather, it quickly went from looking like this…

Bed as of Oct. 9, 2012


to THIS!

Bed today, one month later. It’s getting crowded in there!


I have a backup plan, though. A few weeks ago, I planted a new round of Asian greens in an unprotected bed. They were growing pretty slowly until this recent warm spell. If the temperatures drop again, I might add an Agribon cover just to help them along.

Baby michihili cabbage and kale


Backup Plan #2: The new bed we started Sunday. I’ll be discussing the details of how we construct these in my next post.

The girls help prepare our former pepper and tomatillo bed for another round of veggies.


What did we plant in this new bed? Kale, beets, brussel sprouts, lettuce…

And “secret” seeds – my latest experiment, because I love trying new things in the garden.

Quick! Name that seed!


Want a hint about the identity of these babies? They are a fantastic nitrogen-fixer and cold tolerant to 10 degrees F.

While you think about that, I’ll go get a nice chianti – hold the liver.



  1. Pingback: Calculating Your Garden’s Persephone Days

  2. Pingback: Is Clear Plastic Necessary? Success with Fabric Row Covers

Leave a Reply

Your email address will not be published. Required fields are marked *