Green Houses In Spring
I don’t know how many homesteaders use greenhouses, but if you are intent upon generating most of your own healthy food, a greenhouse of some sort makes a great deal of sense. It can enable a family to have vegetables all year round. Right now we have our greenhouse planted mostly to spinach, and it also contains three types of lettuce and onions. We are also holding our seedlings there awaiting planting in another month or so, receiving that nice full spectrum sunlight. During last winter, we grew seven greens of various types in the greenhouse. There is nothing quite like having a delicious salad during Christmas and New Years holidays, fresh from your own garden. In fact, we kept eating those salads until we ran out, sometime in February. But in this issue of Homesteading Now, we will mostly concern ourselves with spring greenhouse gardening.
Our greenhouses (we actually have two of them now) are unheated, except for the sun. And that is not a bad thing. You can grow quite a variety of vegetables with a ‘cold’ house, meaning an unheated greenhouse. If you add enough heat to keep the temperatures just above freezing, the list of varieties becomes quite extensive. But alas, we are only homesteaders, not market gardeners. It is not our intention to be the first to market with certain vegetables. We do not heat our greenhouse, because we haven’t figured out a fuel that is inexpensive and renewable. Probably the easiest to use would be LP gas, but we prefer not to use fossil fuels in the greenhouse. We have thought about using solar panels to power a DC electric heater in our smaller greenhouse, but doing so is not high on our priorities list. We are quite content to not heat our greenhouses for now. And don’t feel sorry for us; in the middle of winter we work in the greenhouse with snow and wind with perhaps ten degrees outside, and inside the greenhouse it is often above fifty.
The primary problem with an unheated greenhouse is not the temperature outside. It is the hours of daylight during the season, but by spring the daylight hours are increasing appreciably. Spring begins the third week of March and by then we are off and running. First week of March we plant most of the greenhouse to spinach, with various other greens. At first we need to cover the garden beds in the greenhouse with a fabric designed especially for this purpose. It comes in various weights, and we have the heaviest for protecting the tender vegetables. Each layer of of protection that you place over your plants puts you one and a half USDA zones to the south. The fabric represents a second layer (the first is the greenhouse itself). This places the climate under the fabric down around South Carolina or Georgia.
We keep the greenhouse planted in spring leaf vegetables until maybe the middle of May. Then we harvest any remaining leafy greens leftover from the March planting, and switch it over to plants we previously started inside on the heat mats. Last year we planted cabbage and tomato transplants. This year we will be planting cucumbers, okra, peppers of four types, eggplant, and melon.
The inside of a greenhouse can become quite hot on a warm sunny spring day. We have several doors and gable vents in the greenhouse to help move the hot air out and to help keep the air flowing. Toward the end of spring, sometime in May, we actually roll the sides up on the greenhouse. I’ve also attached one inch hex chicken wire four feet wide to the sides to help keep animals from entering and eating all of the hard work.
Since this is my first greenhouse blog, let me take a minute and tell you an easy and inexpensive way to build a greenhouse. Our first structure was made on a twelve by twenty foot rectangle of two by sixes – two twelve footers and two twenty footers. We placed the hoops two feet apart. By the way, since our first greenhouse is shaped like half circles, this type of greenhouse is commonly known as a hoop house. At twenty foot in length and hoops every two feet apart, we used eleven hoops. We made the hoops out of CPVC pipe three-quarter inch in diameter. We glued a series of two ten foot lengths together with a connector. Into this we slid a twenty foot length of half inch reinforcing rod, commonly used in concrete work. Using U-clamps to attach the ends of the hoops in place on the inside of the rectangle, we attached one end first, then reached high and brought the other end around and down. It helps to be six feet tall right about now, which I am. Once you have all eleven hoops fastened in place, you are now ready for the top ridge purlin, and one on each side half way up. You cover the whole structure with polyethylene plastic. It is better to use six mil thick as opposed to four mil thick plastic, and even better to use special greenhouse plastic. You can Google “greenhouse plastic” or do as we did and buy it from Johnny’s Select Seeds. You can also get clips from Johnny’s that holds the plastic to the hoops. All that remains is to make end walls. We made ours with pine boards covered in plastic. You can use your imagination here, and I suggest going online for additional ideas. Our greenhouse has a hinged door and gable vent on both ends. We are beginning our fourth year with this smaller greenhouse and it has had quite a bit of snow on it. We remove the snow by tapping the inside of the plastic with a broom. The snow just slides off. The entire cost was around $275. In a future post I will talk about arranging the planting beds inside the greenhouse.
That’s about it for this week. Thanks again for all the nice comments and emails. Please join us next week as I write about chickens and homesteading.