Triangle cold snap a test for plants, too

If this week’s frigid temperatures have you worried about your plants outside, imagine what Matt Gocke has to contend with.

Gocke is the greenhouse and nursery manager for the N.C. Botanical Garden in Chapel Hill, which sells about 10,000 potted plants a year. Last weekend, with ice, snow and cold in the forecast, he covered about half of them with special blankets to protect them from the cold and wind.

For potted plants that were too large to cover, Gocke says he played Noah’s ark and brought a couple of specimens of each kind into the greenhouse.

“We stuff it pretty full when it’s cold like this,” he said.

The botanical garden grows all native plants, so the cold shouldn’t bother the ones in the ground too much. It’s the ones in pots that are more exposed to the cold air that Gocke has to worry about.

Over at the Sarah P. Duke Gardens in Durham, the collection includes more exotic species, some of which are not well adapted to sub-freezing temperatures. Director of horticulture Robert Mottern says he has a list of plants that includes tea olive shrubs, Confederate jasmine and loquat trees that he knows will get damaged by the cold.

‘You never know’

“You never know how much damage you’re going to get until you see it,” Mottern said.

Mottern has a tea olive at home and has put some blankets around it in hopes of keeping it alive. But there are too many plants at Duke Gardens, and too many large ones, to attempt to cover with blankets, so the staff will keep its collective fingers crossed and see how everything fares.

“It’s all part of experimentation and gardening and seeing how you can push the limits,” Mottern said. “Every five, six or seven years, you’re going to have a winter like this.”

The staff at JC Raulston Arboretum at N.C. State University deliberately doesn’t take any steps to protect its plants from the cold, said director Mark Weathington. The arboretum’s mission is to evaluate how well flowers, shrubs and ornamentals grow in North Carolina, and this week’s deep and prolonged cold will be a good test for many of them, Weathington said.

“It’s going to get as cold as it’s gotten in 20 or 30 years,” he said Thursday. “And we’ve started growing a lot of things that probably shouldn’t be grown here.”

‘Promoting them more’

The Raulston Arborteum took a similar hands-off approach to the severe drought that hit the region in 2007, Weathington said.

“After that drought, there were several plants that performed so well that we started promoting them more and more to nurserymen,” he said. “This will happen with the cold.”

Like Mottern, Weathington expects there will be some casualties and some disappointments, and that’s OK.

“We’re going to learn something about some of these plants,” he said.

This story was originally published February 19, 2015 at 6:36 PM with the headline "Triangle cold snap a test for plants, too."