Q: With all this cold weather and the low wind chills, I’ve been wondering if plants are affected by wind chill. For example, the other morning it was 38 degrees. I didn’t expect it to be that cold. That’s right on the edge for the tropical plants that I usually bring in at 40 degrees. The wind chill was 32 degrees. Do the plants think it’s 38 or 32?
A: Plants basically respond to the actual (air or ambient) temperature. Wind chill comes into play because the wind has a drying effect and can cause damage during colder temperatures by drying out plant tissue, particularly leaves. It is best to make sure to water the root area of plants prior to a freeze and to make sure the roots do not dry out excessively during extended periods of freezing temperatures to minimize this drying effect. The root area should not be soggy wet but evenly moist. Some wind during a frost event, not as much during a hard freeze, can result in less frost. When determining to protect or bring in your plants, consider the actual temperature. If the temperature will be 38 degrees with a wind chill of 32, make your decision on the 38 degrees rather than the wind chill of 32 degrees.
Q: I planted perennial peanut as a ground cover in an area of my landscape. With the bad cold weather, what is the chance of survival for my plants? They are all brown now.
A: Perennial peanut is a tropical plant in origin. It is normal for the foliage and above ground stems to turn brown with the first killing frost. It is not evergreen when planted this far north. it normally will remain brown until spring growth resumes. If it was newly planted, not having time to establish a root system, then there may have been permanent damage from the freezing nights and days that we recently experienced. If the planting had time to establish, it should be okay. Spring will reveal what survived. Perennial peanut needs plenty of sun and room to spread. You can check out this web publication on perennial peanut http://edis.ifas.ufl.edu/ep135 .
Q: Should I prune cold injured plants in my landscape now?
A: It’s best to wait until new growth appears during spring to prune. Pruning too soon may force new tender growth that is more easily damaged from cold weather. Also, the dead leaves and stems on top of the plants may help protect the lower portion of the plants from future cold weather. Winter is not over. More frosts and freezes are likely.