What Plants & Flowers Need Frost Protection in the Spring?

Getting an early start on the garden means planning ahead of time for what plants and flowers need frost protection in the spring. Unexpected spring frosts can severely damage or kill warm-weather vegetables, annual flowering plants and citrus trees. Avoid potential problems by having frost cover on hand. In addition to using frost cover, cold frames or cloches, a glass jar with no bottom can help protect the plants in your garden.

Warm-Weather Vegetables

The urge to plant tomatoes, eggplants, peppers and other vegetables that need frost-free conditions and warm soil is hard to resist on nice spring days. If the soil is warm enough, generally around 70 degrees F, go ahead and plant these warm-weather vegetables. If the soil is still too cold, warm the soil by adding a 3-inch layer of compost or putting plastic on top of the soil. The color of the plastic is not important unless you intend to leave it once you plant the vegetables. If that is your plan, use black plastic or one of the colored mulch film plastics. It is best to go ahead and cover these warm-weather vegetables with a layer of frost cover suspended above the foliage and a cold frame or cloche. Be sure to vent the cold frame or cloche during the day so the plants do not overheat.

Summer Annuals

Summer annuals such as begonia, dahlia, geranium and impatiens are frost-sensitive. This means they will suffer damage or die if frost falls on any part of them--stems, flowers or foliage. If you are growing these plants in a container, simply set the container inside a garage or other frost-free location during the night until after the last frost of the season in your area. If you have already put these summer annuals in the ground, cover them with frost cover, a cloche, a cold frame or an old sheet. Do not lay plastic directly on the plants because if you do not remove it before the sun comes up the next morning your plants could suffer damage.

Citrus Trees

Citrus trees are very vulnerable to damage from cold weather. The larger the tree, the harder it is to protect. Move container-grown citrus indoors to a frost-free location. Use frost cover, a running sprinkler or even Christmas lights to protect larger citrus trees that are growing in the ground. Before protecting an in-ground citrus tree from frost, remove all the ripe fruit. It will likely fall off anyway. Citrus fruit that is not ripe will not ripen once picked. If frost cover is your method of choice, lay it over the top of the citrus tree. Try to anchor it so the wind cannot pick it up and blow it off. An easier method may be to run a sprinkler all night. The sprinkler must be running before the air temperature reaches 32 degrees. Do not turn off the sprinkler the next morning until the ice that forms on the plant during the night has melted. This is the most popular frost-protection method for citrus. The last method is to string Christmas lights in the tree, around the bark and on the ground above the roots. Be sure to choose just one of these methods for safety reasons.

Keywords: frost protection, frost cover, cold frame