If you live in a cold-winter climate, the term “wind chill” is familiar to you. It is a measure of how cold the current combination of wind and air temperature will feel. Even if the morning temperature is not too cold, a chilly wind in the afternoon can create a dangerously cold wind chill effect.
A gardener may wonder about the wind chill effect on plants. Do plants feel wind chill? Does the wind chill factor affect plants? The short answer to both these questions is no, but that doesn’t mean your plants are necessarily safe. Both cold wind and cold temperatures can damage garden plants even if they don’t react to the wind chill factor.
What Is Wind Chill?
How exactly does cold air create wind chill temperatures? Warm-blooded animals, including humans, exude sufficient heat to warm a thin layer of air around our bodies. Called the “boundary layer,” this serves to insulate us from colder air.
That is where chill winds come in. As they blow through, chilly winds blow away the boundary layer of warmed air that insulates us from the cold. After the wind blows away this boundary layer, it strips heat from our bodies faster. The stiffer the cold wind, the more heat it can remove. And the greater the temperature difference between your body and the air, the more quickly heat will be lost. The air “feels” colder than the thermometer indicates it actually is.
Wind Chill and Plants
Are plants affected by wind chill? Let’s start at the beginning. All gardeners know that plants are affected by the cold. And they are affected differently depending on how “cold hardy” the plants are. A plant that is very cold hardy will suffer less from cold temperatures than a tropical exotic. And plants that have had a chance to “harden off” gradually over time will do much better than those exposed suddenly to cold.
But what about plants and wind chill? Plants do not suffer from wind chill the way animals do. They don’t produce heat, nor do they attempt to keep their internal temperatures at a stable heat. Rather, they generally end up at about the same temperature as the surrounding air temperature.
And remember, your plants don’t have nerves, so they don’t “feel” the wind chill effect. Cold, dry winds can damage plants, but it’s the drying them out that does them harm. This is particularly true for evergreens with leaves vulnerable to the winter wind.
Protecting Plants from Cold and Wind
Protecting plants from cold is something most gardeners are familiar with. You have probably applied mulch over soil to keep the roots and base area warmer. Light mulch, like straw or dried leaves can be piled even higher to protect more of the plant. It’s also possible to use garden fabric or even layers of newspapers to blanket the ground. This protects against wide temperature swings.
The same protections used to protect plants from cold can provide a defense against the wind. In addition to mulch and garden fabric, use of mini-greenhouses or even large plant pots turned upside down over small plants keep the cold wind out.