Cold plunge could hurt plants that haven’t gone dormant

A budding bush is covered with a light dusting of snow that fell overnight on April 13. (April 14, 2014)
A budding bush is covered with a light dusting of snow that fell overnight on April 13. (April 14, 2014) File photo

While Monday’s record high of 77 degrees saw lots of green leaves still on Wichita’s trees along with some beautiful fall color, after the temperature dropped to 25 degrees overnight Monday and then to 17 overnight Tuesday, the vibrant green had, in some cases, turned to limp black.

And such signs could mean problems for some plants, extension agent Bob Neier said Wednesday as the cold spell continued and a chance of snow grew stronger for Saturday.

“Time will tell. ... It’s going to be fatal on southern plants,” Neier said, referring to warmer-zone plants that area gardeners had gambled on and that hadn’t gone dormant yet.

For hardier plants, the cold may simply result in more pruning of dead wood in the spring. Either way, there’s nothing to be done now, Neier said.

“People need to quit worrying right now, and in the spring, if it doesn’t leaf out, take it out or cut it back to where new growth comes from.”

Roses, for example, shouldn’t be pruned now unless they’re snagging you as you walk down the sidewalk, he said.

“Some people are trying to clean and rake, and I just encourage raking leaves into your perennials and let them be a mulch versus cleaning it up so much,” Neier said.

The plants that were set up for cold failure were those that were growing vigorously when the temperature tanked, Neier said. That growth usually was the result of recent fertilizing or heavy late-summer pruning, Neier said, neither of which is recommended. For example, he saw some Bradford pears that were topped in midsummer that had been growing vigorously Monday and whose leaves are now black, he said.

That doesn’t mean the trees will die, he said, but that new growth will. Neier expects that this will be one of those years that crape myrtles and roses freeze down to the ground and spring back from their roots.

Botanica still has 38,000 tulip bulbs to plant. Landscape supervisor Pat McKernan expects 8,000 of those to go in Thursday, when the high is expected to eventually climb from a low of 16 degrees in the morning to 31 in the afternoon.

Even though McKernan is relying on volunteers to do the planting, he doesn’t doubt that four to 12 of them will show up for duty, he said.

But it will probably be slow going, because the planters won’t be able to lay the bulbs out on the ground for an extended period, as they usually do for Botanica’s assembly-line planting.

“What does 13 (degrees) do to a tulip bulb on the ground?” McKernan mused.

He said that the soil had been so warm when the cold front hit that the ground is not frozen and planting can still be done. At least for now.

Normally, a cold snap this early in the year lasts only one to two nights.

“It’s unique how long this is supposed to last,” McKernan said of the frigid spell.

He said that the cold damage could include split bark on some trees and shrubs at Botanica, “because they weren’t ready for it. It was 91 two weeks ago on a Sunday and 77 on Monday. They definitely weren’t thinking winter just yet.”

The weather has been typical of January, not November. Botanica still hasn’t blown out its sprinkler system and usually doesn’t do so until Christmas. McKernan likes to water the tulips to kill some of the scent that squirrels pick up.

On Monday, “the mums were still looking good. Now there’s nothing left to worry about,” he said. Ultra violet salvia was about the only flower still in fresh-looking bloom Wednesday, in the wildflower garden.

To put some icing on the cold cake, “we have a good chance of snow on Saturday morning, ” said Chris Jakub, a meteorologist with the National Weather Service in Wichita. The Wichita area could get a couple of inches, he said, with the timing from around daybreak Saturday into early afternoon,

The only sign of any warm-up is the possibility of temperatures in the 40s on Wednesday, Jakub said.

Reach Annie Calovich at 316-268-6596 or Follow her on Twitter: @anniecalovich.

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