GREENHOUSES - EXTENDING YOUR GARDEN'S GROWING SEASON
by Carole Schwalm
How is it where you are? It is October 7 here in Denver, Colorado and the weather report says: Possible frost. The thermometer dipped down to 38° last night. A look out the window and there’s snow in the higher elevations already where I am.
I still have plants with lots of green tomatoes hanging on the vine. There are still blossoms and babies on the cucumbers and bean plants.
Here are suggestions if you are in the same situation.
1. Tomato plant wire cages come in handy. If you put one on top of the other like a cone, secure them together with twine and then cover them with clear plastic the plant is as protected as is inexpensively possible in the cold outdoors.
2. You can make a wire cage, similar to the above, again using a plastic cover tucked in tightly around the plants. Coat-hangers are helpful, btw. A large, clear plastic bag supported by four long sticks works. Anchor the plastic with rocks.
3. You can purchase a cloche or a little glass tent. This is something you’ll also find handy to protect small seedlings in the spring. A bell jar also helps avoid the plant’s transplanting stress. A plastic milk jug with the bottom cut out of it works for smaller plants -- flowers for instance. Leave the cap on overnight.
Unscrew the cap during the day or heat builds up too quickly.
INVESTING IN LONG-TERM SOLUTIONS
… that soon pay for themselves !!
The above are quick fixes in an approaching frost situation. You might want to plan ahead and if so, I have two solutions for you.
The first is a cold frame. This little idea has been around for centuries. It is a box with a glass lid and literally a miniature-miniature greenhouse. The sides of the box protect the plants in a secure, natural environment. The glass lets in light and radiant heat. The cold frame maintains at 20° warmer than it is outside.
While some of your plants may be too tall for this protective device, beets, kale and winter salad greens or any of the many cold weather plants grow and thrive longer. Your cold frame also gives you a head start in the spring. Do keep in mind that your plants need frequent watering and air circulation (that’s what the lid is for).
You can also put flooring, for example, recycled wood like pallet wood, to keep pests away. Certainly an added benefit.
Try to orient your cold frame to the south to take advantage of the late-fall sunlight.
The second is a greenhouse. There are many sizes and price ranges available. We are fortunate enough to have one and it has paid for itself so we are now on the upside because of this year’s abundant crops or our gifts that keep on giving.
If you are considering a greenhouse: how big do you need? And how much can you afford? Many greenhouses are expandable and most gardeners will soon want more space when they see how much they enjoy it. (Look into building permits and if one is necessary if you do go larger).
Hints: Winter is an opportune time to contemplate locations. The best is an area that get Sun during the times between winter sunrise and winter sunset. For summer, the same is true for summer sunrise and sunset. The key is an area with the minimum of shade.
Acrylics are rigid, weigh less than glass, and will not break as easily. You will not lose light. You can also use fiberglass covering; just make sure they are designed for greenhouses as those in a kit are. Polyethylene film is inexpensive, but isn’t as durable. Make sure this is also for greenhouse use.
For more information on greenhouses and greenhouse gardening, check out our articles Greenhouses (part 1) and Greenhouse Gardening
Share your early and late season gardening experience or if you'd like more information.