Unlike greenhouses, cold frames extend the growing season by only a few weeks, and they just use heat generated by the sun—no controlled sources.
Given these unique features, cold frames are recommended for the following applications in which they are most effective.
Overwintering Plants. Fragile or tropical plants that may not flourish in the fall may benefit from being carefully tucked into a cold frame. This will give them enough protection in the cooler months to eagerly thrive in the spring. To adequately prepare them for a long winter’s rest, cut them back before the first frost. Place them in a container with enough soil to insulate the plant, and pack containers tightly into the cold frame. Water them enough to keep the soil moist, and protect them from sunlight so as not to encourage growth.
Starting Seedlings. Whether you plan to transplant seedlings from the greenhouse to the cold frame or start seedlings in the protection of a cold frame, it’s recommended that you have the portable structure in place for at least two weeks to help warm the soil you’ll be using. Unlike when overwintering plants, you’ll want to welcome sunlight into your cold frame to help encourage active growth. Transparent covers, such as clear plastic or glass, are recommended.
Hardening Off Young Plants. The transition of seedlings from the greenhouse or indoors to your garden can be a delicate one. You may opt to move plants out, then back in over a period of time. Or you may want to utilize a cold frame to help. Ideally, you want to wait until the temperatures have stabilized so your plants don’t experience shock in their new environment. Cold frames allow you to open and close to gradually help your plants acclimate to the outdoors. Check for new growth and thick, dark foliage—these are good signs!
Extending the Growing Season. Regardless of when the first fall frost arrives, you can use a cold frame to protect your plants. Because cold frame options are portable, you can take the coverage to the plants even if you can’t move them. Constructing hoop tunnels, then stretching plastic over the frame is a simple way to protect plants from cooler weather and frost. During the day, it’s recommended to pull back the cover as plants are well-adjusted to the outdoors, provided temperatures don’t drop below freezing.
How can you use a cold frame to your best advantage? Contact us and let us know if we can help! Our friendly representatives are available at 800-531-4769, and our website, www.GothicArchGreenhouses.com, is always open.