Saturday, February 21, 2009

Greenhouse Theories

I've been having some good conversations offline about my farming aspirations. I've also been reading about two/three books a week, trying to stuff my brain with knowledge. So I thought I would put some of those ideas "on paper" and send it out for "peer review".

When I decided to grow produce in New Hampshire, I knew I would need a greenhouse. You know, to start seeds in the spring, or something. I didn't know that a greenhouse can actually help you to grow year round.

Most of my greenhouse inspiration comes from Eliot Coleman's Four Season Harvest. The author lives in Maine and makes the bold claim that he eats fresh greens from his garden every day of the year. WOW!

I don't want to steal the thunder from his book. I really recommend everyone buy it, if for no other reason than the man believes in sustainable food and all the good things that I tout on this blog. But his ideas go something like this: We live at a certain latitude (43 degrees) and Southern France is at the same latitude (so same amount of daylight in winter) and they have outdoor gardens year round.

In America, gardening is culturally a summer activity, but it doesn't have to be. You can plant hot-loving plants in the summer and cold-loving plants in the winter. Kales, cabbages, tubers, spinach, and winter greens thrive in the cold. They can tolerate almost a complete freeze and bounce back.

Now of course, it's colder here than Southern France, daylight or not. So you have to protect the plants with a structure, be it greenhouse or cold frame. Notice I said "protect", not "warm". Using electricity or other fuels to warm a greenhouse defeats the purpose of sustainability. Coleman maintains that each layer of "protection", be it the skin of a greenhouse or the glass of a cold frame brings the soil down by 1.5 USDA zones. So if we're in zone 8, inside the greenhouse is zone 6B and if I put cold frames *inside* in the greenhouse, the soil would be zone 5. Zone 5!! Think of the greenhouse as a windbreaker and the inside cold frames as a sweater.

So the plan this year for my greenhouse is to first, build it. I got the 12' x 24x model. I will put pavers down in the first 4' so 4' x 12' will be benched work area. Then the back 4' x 12' will be a brooder for my new layers in April (there is a back door as well). The middle 16' (or 20' when the chickens are grown out) will be for planting in the ground. I will raise hot-loving crops like peppers in the summer, which may not do as well outdoors, and I will raise cold-loving crops in the winter.

Actually, the cold-loving crops grow from Sept to Nov, I will just harvest them all year. They go dormant, but stay fresh, so I don't need to worry about cold storage. They will sit in the ground, protected by two layers of film (greenhouse skin and cold frame "tarp"), until I choose to eat them.

That's the theory.

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