Monday, March 15, 2010

Winter greenhouse wrap up

It worked.
As I have started to spring- and summer-ize my greenhouse I figured I should do a winter greenhouse gardening wrap up. Going into the winter I was really curious how my design and all the thought and planning would work out for my- I mean, my wife’s- greenhouse. In the end I am very pleased with how it performed this winter. However, we did learn a lot too, and armed with this knowledge, I am excited for next fall and winter. Too bad we have to deal with spring and summer. A few weeks ago, I removed insulation from the windows, re-installed the solar window openers, removed the cold frames and started planting a lot of seeds in the greenhouse (native seeds from my list of 2010 Garden Projects, see photo of the flats at the beginning of the post) .Here were our goals for the greenhouse: essentially to grow cold hardy vegetables in an unheated greenhouse all winter, without supplemental heat.

What worked:

  • The greenhouse design with insulated north wall and north roof, steeply pitched south-facing roof, added winter insulation, compost furnace, barrels of water, and cold frames all worked well to achieve our goal of having the greenhouse stay above freezing through the winter (click here to see the winterization of the greenhouse). We only heated it with an oil filled electric radiator for four days when temps were below -10 F. Mainly the reason I heated it on those days was because I was afraid of the water barrels freezing and if they did they would end up cooling the greenhouse of weeks or months!

  • The Compost furnace produced heat, and the compost composted all winter.

  • The solar pool cover storm windows- I like this design so much I am going to build something similar for the shade cloth this summer- removable framed panels. I’ll keep the solar pool cover panels on for another few weeks.

What didn’t, or what to change for next winter:

  • We started many of the vegetables that we grew int he winter too late, this year we will start them in August rather than in October or November to get trough the winter and be productive all winter. There is so little light from mid Dec-mid Jan so we can't count on too much plant growth during this time (I know I read that many times but I had to experience it to understand it, I guess).

  • Pot up more herbs from the vegetable garden and bring them into the greenhouse in the fall earlier
    -I did this with mint and chives, but I probably could have done this earlier

  • I never did add a storm door- maybe this summer I’ll add a storm/ screen door combo- I guess I have to add this to the 2010 Garden project to do list.


  1. I am very envious of your greenhouse... looks os cozy!

  2. I love your greenhouse and your list of do's and don'ts. Great job.

  3. Thanks so much Dirty Girl and Victoria! My wife agrees with you, she loves the greenhouse and spends lots of time out there!