Nothing can be more frustrating than an early frost in the fall or spring. Just when you think you haven’t anything to worry about Mother Nature throws you a curveball. Frost injures your plants when cold temperatures cause ice crystals to form inside plant cells. These crystals then inhibit the movement of water within the cells which damages the plant tissues. The leaves of frost-damaged leaves eventually shrivel and then turn black or dark brown.
The first line of defense against frost damage is trying to be mindful of the type of plants you cultivate and where you plant them. If you opt to add plants to your garden that are considered to be frost sensitive you’ll want to plant them near a southern or western facing wall. The wall will absorb heat during the day and then radiate heat at night creating a microclimate that keeps the plants warmer than if they were planted in other areas of the garden. You can also place these plants near objects such as rocks or shrubs which can provide some physical protection as well.
When cold weather approaches here are some additional measures you can take to protect your plants from frost damage:
- Water the soil around your plants thoroughly. Damp soil holds heat more effectively than dry soil which protects roots and warms the air around your plants.
- Try covering your plants with bed sheets, newspaper, blankets or plastic sheets. You’ll need to use stones or stakes to keep the covering from blowing away. Once temperatures rise in the morning you can remove the covering.
- You can use more natural materials as a covering for your plants as well. Try straw or mulch which can then be removed once the cold temperatures pass.
- Non-LED Christmas lights can emit enough warmth to protect plants from frost damage. You should be careful to place the lights around the plants on not on the foliage itself.
- If you are fortunate enough to have a sprinkler system you can set it to go off in the early morning hours when frost begins to settle on the plants. The extra moisture will keep the temperatures above freezing and prevent the frost from affecting your plants.
While frost damage can be a headache it is good to keep in mind that plants are very resilient. Your first instinct will be to prune damaged foliage but it is best to wait to see how the plant reacts in the first few days after the frost. In many cases, healthy new growth will materialize and you can then prune away any damaged foliage.