Cold spell causes damage

Of course, the big news in the gardening world is the severe cold spell caused by the polar vortex that we had last week.


The official low was 12 degrees at Augusta Re­gional Airport. It was 13 degrees at Daniel Field. I am sure there were places where it might have gotten down to 10 or lower. The Uni­versity of Georgia weather monitoring site in Dear­ing recorded a low of 10.1.

What made it even worse was the fact that it never got above freezing Tuesday, as the high was just 31. I had four water pipes burst at my office that afternoon.

It seems like a long time ago, but it has only been about three years since we experienced temperatures that low. On Dec. 14, 2010, it got down to 10 degrees. However, during the day it reached 41 degrees. The last time we had a day that never got above freezing was Jan. 10, 2011, when it got up to 32 degrees, but the low was only 28. Before that, you have to go all the way back to Feb. 4, 1996, when the low was 19 and the high was 30.

I don’t remember us having any cold damage to plants in December 2010 or January 2011. February 1996 is too long ago for my feeble mind to remember, and the old articles on my computer only date back to 2000, but I am sure we had some.

Some cold damage to plants occurs at certain low temperatures, but what makes a big difference is how long it stays so cold.

The plants most injured will be what we call our zone 8 plants, those that should only be planted from the fall line south.

I have talked to several people, gotten e-mails and seen some results of the cold. I will start with my own landscape.

Several years ago, my co-worker Bill Adams gave me some type of citrus tree that I planted in my backyard. It has not produced any fruit yet but has grown to be about 8 feet tall.

All the leaves have shriveled and are turning brown. It basically looks like drought stress during the heat of the summer. If the entire top dies, I hope it will at least sprout back out next spring from the roots. All of the open flowers on my camellia were killed.

Other things I am seeing and hearing about that were damaged were oleander, podocarpus, climbing fig, sago palms, eucalyptus and confederate jasmine. Plants that might also be affected are Indian azaleas (Formosa and others), pittosporum, fatsia, mahonia, fragrant tea olives, figs and loquat.

With many plants, it is too early to determine the extent of damage. We might not know the final damage until late spring. This is particularly true with fig because there is no foliage on the plants. The key point is to remain patient and not cut back plants that we think are dead.

Any camellias in tight buds that have not bloomed yet should be fine. Take a wait-and-see approach and do touch-up pruning in late March and April.

If plants such as pittosporum or azaleas die in early summer, look for split bark down the stems. Bark splits from quick changes in temperature. Often shrubs will leaf out and die a slow death over several months.

Many plants such as oleander, confederate jasmine and fig might be killed to the ground but should come back in the spring, provided they had more than one growing season.

It is unlikely that some of these plants will be completely killed, but if it happens, replace them with the same variety of plants. We only get these type freezes about every 10 to 15 years, and the plants I’ve listed are hard to substitute in our Southern landscapes.

In our lawns, St. Augus­tine is as brown and dormant as I have seen it in several years. Some St. Augus­tine and centipede could likely have some damage, but it should be less than 20 percent. It there is any dead, you will see brown patches during spring green-up. Both lawns should fully recover by June if fertilized properly and if we don’t have a bad spring drought.

On the positive side, the cold winter makes our plants more dormant so they can tolerate lower temperatures. With all the rain before the polar vortex, there was plenty of soil moisture, and plants that are well-hydrated can take the cold better.