After covering 200 foot of peppers with new A-frame greenhouse last year, I am a convert! I re-read Elliot Coleman’s book on four season farming as well. While we live in a much milder climate than Maine, it franklywas cold and foggy almost every day last summer and many of the warm season crops failed to grow.
I finally gave up on Charante melons and plowed them under. They never set any fruit at all! There are a few very small Sugar Baby watermelons on one patch, but none on the other which is more exposed to the wind.
But in the greenhouse (unheated like Coleman’s) it is like the tropics even if it is overcast and blowing outside. We will no doubt have to go through a long learning curve to get the full potential of these greenhouses, but I can imagine eggplant, tomatoes, peppers, and maybe even melons next year grown indoors. I have been very pleased that the bees find their way inside from the open ends and the peppers have set a lot more fruit than the ones outdoors. Check this out:
We have already set out tomatoes and basil in tow greenhouses and are getting ready to plant a third with zucchini.
I should repeat here that these greenhouses cost about $1 per SqFt to build, can be put up in a few hours and as importantly, they can be taken down and stored or moved in a short time. So far, they seem very capable of handling major winds, a design criteria that was critical to us. Because they are made from 10×10 panels, the can be made any size, from 10 ft to 200ft (or more), so are ideal for a small yard as well. I showed this design to a home gardner the other day and they are going to build a 10×20 house for their back yard. This will cost about $200, a small price to pay for a year round garden!
You can see from the two panels on the right that the wind pressure presses the plastic inward on the windward side. This is an advantage because it doesn’t flap around, which would damage it at the point of fastenings. The wind pressure pushes the entire greenhouse into the ground, which results in a more stable structure.