We installed a cold frame in our vegetable garden in order to have some fresh vegetables in winter. We did get some cold loving vegetables like Chinese Broccoli, Swiss chard, kale, carrots and mustard greens. Several times the vegetables inside wilted from the cold when we couldn’t get access. In the middle of winter when snow piled two feet up the frame, we couldn’t get the door open without a lot of digging. But it still gave us a good head start for spring vegetables and we get to have fresh vegetables early in the season despite the seesaw weather.
The seeds I sow in November like spinach, Bok choi and mustard greens, sprouted early and became our first salad crops.
Then I sow more cool weather vegetables like Mizuna, Shungiku (Tang Oh), Chinese broccoli, Corn salad, arugula and more of spinach and mustard greens in March when I got access to the inside. These will become our second crop.
Since the cold frame has no ventilation, early spring is when we have to be careful. We need to leave the door open on hot days otherwise the vegetables in there will be cooked. I devote this patch under the cold frame for growing leafy vegetables because it provides shade during the summer months. Once the plastic is cover removed, I grow Bitter melon and beans and let them climb up the frame as they provide shade for the vegetables below.
With a couple days of heavy rain other vegetables in the garden double their size. Asparagus shot up a few inches a day with rain. We were supposed to cut them when they reached six inches high but…
After it was fed and with plenty of rain, our garlic, both Siberian and Rocambol garlic, got much bigger very fast. We had a good garlic crop last year and still have some left in the basement. So far this year should be good too.
We devote only a small part of our backyard for vegetable gardening and I’m always looking for a way to add more plants and increase productivity in the existing space. Though we have put a deer fence up around our backyard, we still have to put a low fence around the vegetable garden. If we don’t, there would be nothing left. Deer cannot get in our back yard but rabbits, woodchucks, squirrels and chipmunks are still able to sneak in and enjoy what we grow. So we are limited to growing vegetables within this little fenced in area, therefore I try to make every inch work to its maximum productivity.
Looking back at the last season, I note what worked and integrate it into the coming season along with whatever adaptation increases efficiency. The method described below can be used for any plants that grow vertically, not just vegetables.
Aside from incorporating different plants in any one plot, I also grow vertically. While most gardeners grow beans on a cone shaped ‘teepee’ I believe, I put up a trellis for beans that’s over the path, high enough to walk under, and grow beans on each side. Last season, I put one up by the vegetable garden entrance. It worked well and when the beans were fully grown and had developed pods, it looked beautiful and provided easy access for picking the beans too. The trellis can be moved to any part of the garden easily when needed or I can grow different vegetables on it.
Once the weather was warm enough to remove the plastic from the cold frame, I put up a net in its place, see the first photo, to filter and soften the sunlight. It reduces the light by about 50%. Leafy vegetables like lettuce, Mitzuna, and Pac Choi prefer a little shade. In the middle of summer, when the temperature is high and the sunlight is strong, these leafy vegetable will bolt easily and the lettuce will turn bitter. With shade over them, they can take their time to grow, their leaves are crisp and sweet and the soil will dry more slowly. I grow Bitter melon on the side of the frame structure and let them entwine themselves up the frame. I gradually roll back the filtering net as the melon plant grows allowing it to take over shading the vegetables below.
One down side of having the vegetables grow up the frame is that I have to cut them all down when the temperature threatens to drop close to freezing. I need to put the plastic back on and turn it back into a cold frame again. Most gardeners leave the plastic on but open the ends of the structure to let the air flow through in summer. I could have done the same but I would lose growing space on the top of the structure. I would also have to put a smaller frame over one of the 3’X18′ plots and cover it with a sunlight filtering net to grow these vegetable in the heat of summer. I prefer to kill two birds with one stone: shade the vegetables and have extra growing space.
We set up a cold frame for the first time last autumn but it didn’t do much for us this winter because we installed it so late in the season. However, it provided us with a place to start our vegetables early. The seeds were sown in March when some days were still hovering around 20ºF here. We were able to pick our first salad of the season in April when temperatures outside were in the mid 30ºF to low 50ºF.
The weather is still unpredictable. Temperatures have been swinging between 70ºF daytime and a low around 40ºF at night. It’s still too cold for many vegetables to germinate outside, but I have sown scallion, Mustard ‘Dragon Tongue’ and Oakleaf lettuce in the plot outside the cold frame and it seems to be taking them a little bit longer to sprout. But I can wait as I still have a lot of vegetables to pick from in the cold frame.
Aside from being able to grow leafy vegetables in the cold frame on an early schedule, I’m also able to use it for strengthening the seedlings. Plenty of sunlight can get through the plastic but not direct sun and it stays warm enough in there to avoid stunting the growth of the seedlings. I have to be careful to open it up during the day when the temperature reaches above 50ºF. It becomes a sauna in there if I don’t open it. Too hot or too cold is never good for growing anything.
This one worked so well that I’m tempted to get a larger one that will cover the entire vegetable plot. Maybe I could go through winter without ever buying salad from a store.