A while back I explained my plan to extend the garden’s growing season by building domed covers over my raised bed garden boxes and planting cold-tolerant plants. I thought I’ll let you know how that’s going and what I’ve learned from the experience.
Fresh Vegetables in January
I planted mesclun lettuce, leaf lettuce, carrots, onions, chard, spinach, garlic, and Brussels sprouts. On a weekly basis I’ve been able to harvest the lettuces, carrots, onions. Chard comes in a little more slowly. The spinach is alive but pretty well stopped in its tracks as far as growth goes. I think this is mostly due to a lack of sunshine; which I will discuss in a moment.
 I didn’t plant more than a couple of squares of each plant because I didn’t want to be inundated. That need not have been a worry. We get enough each weekend to make one good salad, which will provide dinner once and provide a side salad once or twice for lunch through the week.
 My herb bed is also doing well and we can clip rosemary and oregano as needed. The sage has gone dormant, so I don’t take cuttings from that. I moved a basil plant into my office and that serves our needs well since I have to clip it aggressively to keep it from bolting. I’ll plant fresh seedlings in the herb bed in the spring.
What I’ve Learned
The biggest mistake I made was in planting beds that are in a shaded area during the winter because the sun sits lower in the sky in winter than it does in summer and trees along the edge of my property block the sun. In the summer this was not a problem. Next year I’ll need to put in more boxes and the winter garden will be higher up the slope where full sun is received most of the day.
This lack of sun is compounded by the fact that the plastic covering the houses is semi-transparent, so it may be blocking some of the sun. Whenever possible I go out and pull the covers off the beds on warm sunny days.
I was afraid that watering the beds would become a chore since I had to disconnect and drain the water hose for the winter. But this has not been a problem. Rain that falls on the cover slides down the sides and into the edges of the box. The vermiculite in the mix then helps hold the water for the plants. And because there are not many warm, sunny days where I pull the covers, the moisture that gets inside tends to stay there. Evaporated moisture condenses on the inside of the cover and falls back to the soil as it gathers into droplets. I have not had to add water even once so far.
One thing I did think to do was to make slits on the plastic where it wraps around the lower side bars. This allows the water that runs down the sides to escape and fall back into the soil instead of building up in the pocket this wrapped plastic forms.
I have learned that there are some PVC pipe fittings that would allow me to build a “house” shaped roof rather than bending the piped into a hoop. The hoop puts a lot of tension into the system and this can cause some problems with joints popping loose and legs not wanting to fit into their sockets. Building domes with short straight sides and a peaked roof would take all the tension out of the system.
Conclusion
I’d say the project is a success; it is providing us with fresh food and will have a great start on the early spring crop because much of it is already in the ground. I need to be more mindful of the suns winter position and put out more plants next year. But it has worked well.
