Try these simple and inexpensive methods to extend your growing season into the fall and winter…
You may think that your climate is the main determining factor in how long you can keep your garden growing each year, and while this is partly true, it is also true that you can extend your growing season (in either direction), regardless of where you live. Even in cooler climates, you may be surprised how long you can keep plants alive outdoors with just a bit of protection.
Many cool weather crops don’t care for summer weather, and their growth may slow or even stop if it gets too hot. Crops such as these are best planted very early in the spring, or in late summer for a fall and winter harvest. If temperatures dip much below freezing, however, even cold-hardy vegetables will benefit from some protection.
However, this doesn’t mean you need to invest in an expensive heated greenhouse. Many crops will survive quite well with just the protection of row covers, a cold frame, or a low-tunnel hoop house.
Row covers can provide a slight-t0-moderate degree of frost protection, and are also handy at keeping tender crops safe from insect pests. You can use plastic or garden fabric, but plastic may be better at holding in the heat, so you’ll want to avoid that if the days are still warm, or you may end up cooking your plants! Both are quite affordable, and you can use simple wire hoops to support the fabric, or just use lightweight fabric and allow it to rest on top of the plants (this is often called “floating row cover”).
You’ll want to weight down the edges of the fabric (or plastic) with soil, rocks, or other items to keep it from blowing away and keep insects from entering.
This is the simplest and least expensive method of frost protection, but it only goes so far. If you need greater protection, you will want to go with a hoop house or cold frame.
Hoop houses can be large enough to stand up in, such as a small unheated greenhouse covered with polyethylene, or they can be as simple as a piece of plastic suspended over a garden bed using flexible or PVC hoops (which can be covered with heavier fabric if needed). Both options are relatively inexpensive for the home gardener, and much more economical than a permanent greenhouse.
I use pieces of old fencing covered with row cover in the fall. When temps get into the mid-20’s or below, I throw moving blankets over these, and if snow is predicted, I add sections of PVC pipe underneath to help prop up and support the fencing to keep it from crushing the plants. I have harvested cabbages in February here in Central Ohio with this method, and we have even had kale and collard greens survive the entire winter.
Cold frames are another good way to extend your garden season. They are typically constructed as a bottomless box on top of a garden bed or in a sheltered corner near a building. The soil helps collect and trap warmth, and the top of the box is typically made of glass such as old windows. You can also use heavy plastic sheeting, but glass will usually perform better.
Make sure your cold frame is located where it can get plenty of sun, as this is key to keeping the temperature inside above freezing. The lid of the cold frame is usually adjustable to allow airflow if needed.
Cold frames are a great place to give spring seedlings a head start before it’s warm enough to put them out in the garden, or you can also grow items such as lettuce and other salad greens directly in the cold frame for an ongoing fall and winter salad garden.
Cold frames may be either permanent or portable, and while kits are available, it’s almost always more affordable to build your own. Keep an eye out for scrap lumber and old or marked-down windows at yard sales, flea markets, or your local home and garden store, and you won’t have to spend much to protect your plants from winter weather.
Here’s a helpful visual of these 3 season-extension options: