The first frost of the year always gets the attention of the more serious gardeners. For the record, we got our first frost this past Friday morning on November 1. Significantly, that’s about two weeks earlier than our normal, historical average first frost.
The first frost brings about an end to the growing season of warm season vegetables and some plants your landscape. My Canna lilies had a decent amount of frost on the leaves and should soon be dying back. I’ll break out the loppers and cut them back and add them to the compost pile.
My Bermuda grass, in the pasture and the lawn, will soon be turning brown and is done with growing until the late spring when nighttime low temperatures stay in mid-60’s.
Don’t even think of adding a “winter-izer fertilizer” to your lawn now. Giving nutrients to a warm season lawn after frost is like to serving supper to someone in bed, asleep, at 1 am. It’s not going to be appreciated!
Yet, some garden plants (think kale, mustard greens and cabbage) are still doing well and can continue to produce without a hard freeze. Garden vegetables such as beets, broccoli, carrots, cilantro, English peas, Snow peas, and spinach can take even a slightly colder freeze, just below 30.
So what can you do to protect your cool season plants that are still thriving?
Irrigate before a freeze. A moist soil can hold four times more heat than a dry soil. It will also conduct heat to the soil surface faster than a dry soil, aiding in frost prevention. In a study performed years ago, the air temperature above a wet soil was 5 degrees F higher than that above a dry soil and the difference was maintained until 6 a.m. the next morning.
With all the rain that fell just days before Friday’s cold spell, we may have had protection that we didn’t have to put out ourselves.
Covering plants can with a bed sheet can give you 2 to 5 degrees of protection. The covers can be laid right over the crop or can be supported on stakes. The varying degrees of protection lies with whether the cover touches the plant. Any material can be used to cover plants; however, woven fabrics are better insulation than plastics or paper.
Cabbage and onions will tolerate even colder temperatures of less than 28 F. If you think that you’ve passed up time to vegetable garden, I’d encourage you to keep on planting. For those warm season plants in the garden and landscape, we’ll see them again in the spring.