How to Protect Plants from Freezing Temps
Temperatures of 32° F. and below are in our forecast for Friday night. Wondering what to do to protect your plants from these potentially devastating temperatures? Don't panic; here is some advice from Tony Fulmer, Chalet's Horticulture Officer.
Prioritize - The early season, cold-indifferent annuals and veggies (pansies, violas, snapdragons, Brussel sprouts, cabbage, onions, to name a few) will happily survive. Still, always better safe than sorry when it comes to sub-freezing temperatures. Do think about protecting even the early season annuals that you may have already planted. Place sturdy stakes in the ground around the periphery (if the area to be protected is large place stakes throughout the bed) to keep the cover from sagging, touching or breaking the plants.
Cover with old sheets, lightweight blankets, canvas tarps (although heavy) – anything woven (NOT PLASTIC) that will trap and hold warm air. Place the fabric over the stakes and leave enough extra that you’re dropping the edges to the ground- just like a tent. You’re trying to trap the ambient heat from the soil and keep the air around the plants from freezing. Plastic MUST NOT be used against the plants as it simply transfers the cold temps, especially if it should touch plant tissue. Plastic can be used OVER the top of your sheets, blankets, etc. as an extra layer of insulation, but never by itself.
Potted plants, especially in flower, should be moved into the garage or inside if you really want to maximize protection. Always remember that flower tissue is “softer” and more apt to suffer freeze damage than leaves. While spring flowering bulbs like tulips, hyacinths and daffodils have insulating mechanisms, why risk it? Play it safe and protect them.
Newly planted perennials that have been greenhouse-grown may also be “softer” and possess more susceptible-to-cold foliage than their established counterparts that have spent the winter in your garden. Again, make the effort. Consider covering them too, especially if they’re away from a house, structure or overhang that might afford them a few degrees more warmth. When it’s this cold even a few degrees can mean the difference between death, serious damage or survival.
Newly planted trees and shrubs that may have been brought in from milder areas of the U.S., are seasonally much further along than their Midwestern-grown counterparts. Plants that “look” delicate, have thin leaves (ex: Japanese Maple) would undoubtedly benefit from covering. If branches look fragile gently tie them up with twine (no wire, please) before covering. Again, NO PLASTIC!