Winter is hard on your flowers. Tender annual flowers like impatiens can’t survive a frost or temperatures below 55 degrees. Half-hardy annual flowers can survive brief, light frosts and temperatures of 35 degrees to 45 degrees. To be safe, protect all your plants when the temperatures drop.
If the forecast calls for a cold front or frost, use the methods below to cover your flowers.
How to Cover and Protect Flowers from Frost and Cold Nights:
- Water the area surrounding your plants the night before a frost to protect them from freezing. Wet soil releases moisture in the air, which raises the temperature and keeps plants warmer throughout the night.
- Choose a cover:
- Use old sheets, drop cloths, tarps, burlap or newspapers.
- If you have cardboard boxes, open them on one end, turn them upside down and place them over your flowers. Tape any cracks to keep out the cold air.
- Use empty pots, buckets, milk jugs with the top cut off, or other containers made of wood, plastic or clay to cover your plants. Be sure they’re tall enough to fit over plants without crushing them. If there are drainage holes in the pots, put rocks or pieces of broken pots over them.
- Cover your flowers with sheets of plastic. Don’t use thin plastic bags, which can freeze your plants.
- Use pre-made row covers to shield your plants from frost. Some are made of breathable materials, so you don’t have to take them off in the morning and put them back on at night.
- Place covers over your plants before the temperatures hit freezing. If you’re using plastic covers, wait until twilight to avoid the sun cooking your plants through the plastic.
- If your cover is lightweight enough to blow away in the wind, weigh it down with rocks or bricks.
- Remove cardboard or fabric covers as soon as the weather warms up. Remove plastic covers as soon as the sun rises.