When it comes to deciding whether trees and plants need replacing, local experts tell homeowners to be patient as plants emerge from dormancy and re-sprout at different times.
John Farfaglia, horticulturist with Cornell Cooperative Extension of Niagara County, knows that home landscapers are eager to clear out remaining winter debris and get their yards in shape.
“They know spring is coming, they get out on early days and don’t see signs of life,” he said. It can lead to premature decisions to cut trees and dig out plant clumps.
“Every season is different,” Farfaglia said.
“Years like this — when we have a real winter — people will find things coming out a little later than normal.”
April is the optimal time to prune damaged branches from trees and bushes, and horticulturists have a trick for telling the quick from the dead.
“You can scratch the bark of one of the branches and see what kind of color the tissue is underneath,” said Carolyn Stanko, professor and coordinator of horticulture and biology at SUNY Niagara.
“Generally what you’re looking for is a light creamy or greenish color,” said Farfaglia.
Anything that is brown and dried out in the center is dead and can be cut away, Stanko said.
The scratch test can be used on any plant that grows bark, from shade trees to hedge shrubs, hydrangeas and roses. With woody plants, Farfaglia said to keep in mind that tops — upper limbs — tend to be killed first from winter conditions. This can leave lower parts of trees and shrubs still able to grow out and replace branches when the weather warms.
Some trees, like redbuds, golden chain, mimosas, and butterfly bushes can die to the ground and re-spout from roots alone, Farfaglia said. They may not show signs of regrowth until summer.
“Don’t give up hope, especially this early,” Stanko said. “Maybe you scratched a dead branch but the rest of it is fine. Don’t be too eager to rip it out.”
“What you might find on an established tree is, the graft might die but the rootstock survives,” Stanko said. Weeping cherries and weeping mulberries are examples of trees that have one variety as the trunk, and a weeping variety attached at nearly 4 or 5 feet. Freezing can damage the graft, killing the top, which allows the trunk to grow up and out for the first time.
“That part of the tree will sprout,” Stanko said. “It might not look like you wanted. You don’t get the beautiful weeping branches.”
Perennial flowers that don’t grow stems and leaves until June include hibiscus, baptisia, milkweed, Russian sage, butterflybush, wisteria, and some tall grasses, Stanko said. Hydrangeas take time, and rose of Sharon and Clethra, also known as sweetshrub, are among the last shrubs in spring to regrow.
“Don’t go out and cut down your perennials and grasses until daytime temperatures are consistently in the 50s,” Farfaglia recommends. This plant material provides protection to pollinating insects during cold weather, he added.
Stanko said butterfly bushes regrow their entire top each year, so they can be cut to the ground without losing summer flowers.
To avoid losing blossoms on spring flowering shrubs, prune them once in early summer, Stanko said. Azaleas, forsythias, spireas, dogwoods, and ornamental fruit trees will develop new flower buds in summer, which will overwinter for a show next spring.
However, Stanko said, patience won’t make a difference when it comes to disease and moth damage on boxwoods.
“We are seeing blight in all of Western New York,” she said. “Between the disease and the insect, boxwoods are really suffering. It’s not going to go away. A lot of people are replacing boxwoods with Japanese holly.”
While there are products available for boxwoods, Stanko said treatment has generally been a losing battle. “If you’ve got it, it’s going to take everything out,” she said. “If you have just a few boxwoods in your landscape, I would rip them out.”