Now that the shock of our recent historic Gulf Coast snowstorm is starting to be a “rear view” memory, it’s time to take stock and see where the dust has settled. Y’see, in the world of horticulture, the snow is just the good and pretty stuff, but it’s the cold that matters. At my home in Grand Bay, I woke up the morning after the snowstorm, and to my utter shock, the thermometer said 10°F! Well, ya’ll, that’s cold! Bellingrath, while not having a weather station on-site, probably bottomed out at 13°F. So much for those forecasts of a warm and balmy 18°F, I guess. [Deep sigh]
I’ve been around the southern U.S. long enough to say that the best way to characterize our winters is to call them generally mild but infrequently punctured by bitter cold. (With our changing climate, I would have previously said “every now and then” instead of “infrequently.”) We are definitely getting warmer on average for our winters, but, averages have a way of being uncertain, eh, especially since plants respond to extremes and not to averages? Well, despite our well-known and respected USDA Plant Cold Hardiness Zone Map, which puts Bellingrath at somewhere at a zone 9a (winter lows of 20-24°F), 13°F is actually a zone 8a temperature (winter lows of 10-14°F). And that, folks, is a winter temperature that definitely breaks the average.
What is the result of all of this babble, you might ask? Well, if you’re looking out your kitchen window or you’re driving around town, you are noticing azaleas that appear as much “brown” as “green.” You may also be seeing camellia flowers look a golden-brown color that you’d rather see on fried chicken than on camellia flowers. This tells you, then, that what just happened is real, and it was beyond the typical conditions from our recent winters. At Bellingrath, the camellia flowers that were fully open were killed, and flower buds that were partially open were either badly burned or killed outright; however, the unopened flower buds are fine, and the plants didn’t miss a beat. If you grow the old-fashioned bottlebrush shrubs (Callistemon citrinus), then their leaves have a nice tan-gray appearance right now, but the plants should be fine. Tasmanian flax-lilies (Dianella tasmanica) now have chestnut-brown leaves, but they should flush bright green new foliage once spring arrives and soil temperatures warm. On the “this is a good thing” side, camphor trees (Camphora officinarum), especially those growing in open areas, saw their foliage badly burned, which is great since this is a major invasive pest species in our forests. Also, the California and Mexican fan palms (Washingtonia) have browned up pretty badly, but should send out new leaves in spring to early summer. Remember ya’ll, with cold damage to plants, it is always better to wait than to hurry up and cut dead leaves and stems back.
A few newer-to-us plants that we are now growing at Bellingrath as “perennial” plants, meaning we don’t rip them out the ground as soon as their flowers fade, tell a few good tales. 1) Chamaedorea microspadix, the Mexican parlor palm, was untouched by the cold. Our plants came from Cathedral Basilica of the Immaculate Conception in downtown from older plants growing there that produced a nice crop of seeds three years ago. 2) Two of the “mangaves” (pronounced mann-GAH-veez) that we’ve acquired and are testing did great – ‘Macho Mocha’ (who doesn’t love that name?!) had a little bit of foliar burn, and ‘Falling Waters’ was unscathed. 3) Ctenanthe setosa, an old houseplant I learned back in the 1980s, died back to the ground, but I learned three years ago from Dr. Gary Knox (Professor of Horticulture, retired, University of Florida, North Florida Research and Education Center in Quincy, FL) that this plant has grown in the Tallahassee area for decades as a perennial, and so it should be perfectly fine come spring. Who would ever have thought that a close relative of the prayer plant (a common, old-fashioned houseplant) could be so cold hardy?!
Tell us your tales, both of woe and of glory, of plants from your gardens. We are eager to see what you’ve learned from our recent bout of record cold temperatures and a thick blanket of insulating snow!