GROWING FOOD IN THE GREENHOUSE
The greenhouse at Golden Gaits Ranch is complete and plants are growing beautifully. The solar collector, used to heat the greenhouse and our household hot water, is fully operational. During our winters the greenhouse provides us with greens such as lettuce, spinach, kale, chard, and bok choy. We’re continually eating fresh tomatoes and zucchini. I’ve harvested turnips, rutabagas, beets, daikon radish, kohlrabi, Chinese cabbage, cauliflower, cabbage, and broccoli. Herbs growing are thyme, rosemary, cilantro and basil. Summers provide us with tomatoes and winter squash, with other things growing in the outdoor garden. Please see the blog post, “Garden Planning & Implementation” to read more about our greenhouse construction.
For the month of January 2018, the greenhouse temperatures averaged 74°F during the day, and 56°F overnight. (The outdoor temps ranged from -9 to +62, averaging 11 at night and 48 during the day that month.) We had been installing insulation over the glazing each night to retain the heat that has been collected during the day, but decided that was unnecessary. The floor and soil in the beds are heated from the sun during the day, and the soil stays at about 65-70°F. The pond (shown at left) is filled with water to act as mass thermal storage. We are now using a heating unit that draws its heat from our solar collector. We use a small, electric space heater when the sun doesn’t shine and the solar collector has run out of hot water. These are all automated to turn on and off as needed.
WHAT GROWS IN THE GREENHOUSE?
After three years, I’ve learned a few things about how things grow and when and where I should plant things in the future. I’d had high expectations that things would grow like they do outside, since the optimum warmth would be kept high. However, without the addition of an artificial light source, the plants receive fewer hours of light per day and grow much more slowly than they do in summer outside. As the spring days gradually getting longer, the plants grow faster. Some things are do better than others: the cold-season crops such as kale, chard, spinach and lettuces have done well. The tomatoes are productive, but the tomatoes are smaller and ripen much more slowly than they would outside. The sweet peppers don’t do well and I don’t know why, but the hotter peppers did better. A couple of the hot peppers (“Biggie Chile”, an Anaheim type pepper) got so tall they unexpectedly shaded the plants behind them. Since our greenhouse is not as tall as stand-alone greenhouses typically will be, I can’t plant tall things. I’ve learned to get compact plants, especially tomatoes. The only exception to that is I usually plant one or two indeterminate tomatoes that can be trained along the beam above.
When planting the beds by the windows, I had planted some of the larger things, such as kale and swiss chard, at the back of the beds, thinking that the shorter plants in front should be more accessible to me, but I wasn’t thinking about the larger plants by the windows shading the plants closer to the inside edge. Although the shorter plants may be harder to get at, they should have been planted closer to the windows behind the taller plants from the perspective of where I stand to work. In addition, the larger plants near the windows make it more difficult to put up the insulation each night.
I’d read that growing zucchini vertically is a space saver, and a good way to grow it in a greenhouse. I tried that, and I’m glad I did. Rather than having the plant sprawl across the bed, it is growing nicely upward, saving space around it for other things. The zucchinis are easy to see and easy to pick. Unfortunately, a couple of turnips that were growing behind it didn’t get much light and grew very slowly. (I had thought that they would grow more speedily and be harvested before the zucchini got too big, but that didn’t happen.)
In the summer I’ve been using the greenhouse mostly for tomatoes and winter squash. In the summer of 2019 I experimented growing winter squash both in the greenhouse and outside. I chose some varieties that are considered “compact” and had the fewest days to maturity (around 80). The greenhouse squash were started slightly sooner than the outdoor, and ripened slightly sooner as well. In both cases I pollinated them by hand, as we just don’t have many pollinators here. The outdoor squash was just barely ready to pick before it threatened to freeze. Next year I’m planning to do the same thing again–a little of each in both places.
November 2019: I’m beginning to get a better feel for what grows well in the greenhouse and what does not. I’m planting more of the better producers (cabbage, broccoli, zucchini, lettuce, spinach, basil) and have quit growing things that either didn’t do well or attracted too many aphids (rutabagas, turnips, chinese cabbage). I tried some onions and garlic the first year, but they did not do well. I believe now that they need a cold season to make bulbs. Leeks grew, but took a VERY long time to get big enough to harvest (almost a year).
I’m beginning to get a better feel for when to start something new early enough in soil blocks to be planted in a spot after something else has been harvested. Each time something is removed, I add some compost, vermicompost and fertilizers to the spot before planting something else. At times I’ll leave a spot vacant if I know I will need the space later.
In the spring of 2019 I tried something new: bush beans. I had some seeds left from the previous summer of Mascotte beans, which I knew were small, compact plants. I started them in April and harvested them in July. They are advertised as maturing in 50 days. These took about 80 days, but considering the low light of April, perhaps that’s to be expected. 40-50 plants produced over 4 lbs of very nice French beans, and I was quite pleased with the result. I felt that having beans in that spot should have helped fix nitrogen in that section, so I plan to do another batch of beans in another spot in 2020.
Tim asked me one day whether there was anything I’d do differently. Not much, but I’d like it to be taller. If it were taller I could hang more plants! I’d also kind of like it to be larger in area, but keeping it to this size is good for me so I won’t overplant and have too much. This is a good size for just the two of us and will do just fine. I don’t really *need* more space. (In 2020 we started some cold frames which allows some space in the greenhouse for other plants, like more broccoli!)