Trees may keep their leaves for a while

Many leaves were still on the trees when frigid weather befell us a couple of weeks ago – and they may hang on for winter.

That will be a danger if we get an ice storm, because the ice will have all those leafy surfaces to cling to, and the added weight would bring tree branches down easier.

“I think we kind of dodged a bullet” on Friday morning when the forecast included a chance of freezing drizzle that didn’t end up freezing, said Jason Griffin, director of K-State’s John C. Pair Horticulture Center in Haysville. “Can you imagine all of those leaves coated with ice or a wet snow?”

Fall hadn’t altogether moved along when the winterlike weather arrived Nov. 10, dropping temperatures steeply and suddenly. The John C. Pair Center reached a low of 1 degree during the cold snap, Griffin said.

Many trees still had a full canopy of leaves. Where they are still green, it means the trees did not go dormant before the cold weather hit, and the leaves may stay there for a while, extension agent Bob Neier said.

“The leaves are freeze-dried on the trees,” Griffin said. “It’s just silly. ... The pear trees are these green statues standing up.” In trees that were in the midst of turning color, the pigments are frozen in the leaves, he said.

“The good news is we’re having extended fall color,” community forester Tim McDonnell said, laughing.

The green leaves may simply hang on until they rot or until new leaves push them off next spring, Neier said. That means they eventually will grow ratty as they disintegrate. And that we’re missing those huge piles of crispy leaves we could usually jump into come Thanksgiving.

Instead, the late-November landscape just becomes more strange. The color of leaves that were fiery red when the snow was falling last weekend has started to fade. Some green leaves have bleached white, giving the appearance of flowers from a distance. Leaves on one red maple at Botanica have washed out to a papery pale pink and coral.

Late-summer pruning or fertilization of trees pushes on new growth and contributed to keeping some of them from going dormant, Neier said. This year’s experience is an example of why it’s best to wait until trees are going dormant to fertilize them and until late winter, just before they come out of dormancy, to prune them.

As far as damage to the trees, “we’ll find out in the spring,” Griffin said. “I guess if a tree was still pushing new growth, we’re going to see considerable stem damage.” That will require pruning dead wood back to a live bud, but the trees should bounce back, he said. If a tree already had problems, the dry conditions when the temperature plummeted could compound them, McDonnell said.

As for the latest crazy turn in the Kansas weather, Griffin said, “I have given up on deciding what is normal around here.”

This story was originally published November 22, 2014 at 5:33 PM with the headline "Trees may keep their leaves for a while."