It looks to be a tough year for our suburban gardens.
Last week, I told you about the new downy mildew that’s killing the shade-friendly impatiens that so many people rely on every year for easy color in their yard. (Here’s a link to my article/post, “A Devastating Downy Mildew Is Striking Down Hybrid Impatiens Plants”)
Now we’re learning about a new boxwood blight, a fungal disease that’s been seen in Westchester, Long Island and Connecticut, says Margery Daughtrey, a plant pathologist at Cornell’s Long Island Horticultural Research and Extension Center in Riverhead. “It came in very fast.”
(Photos from Margery Daughtrey, who says this one was shot in Westchester by arborist Tom Marino, of SavATree in Bedford Hills.)
It was first seen in the United Kingdom in 1994, she says, and has also appeared in North Carolina recently. It is not known how the pathogen was introduced into this country.
Like the impatiens downy mildew, the disease spores are easily spread by wind and wind-driven rain. It can spread quite quickly in warm, humid conditions.
Unlike the mildew that kills impatiens, this newly arrived disease is a leaf and shoot blight that doesn’t attack the roots of the plant, Daughtrey says. But defoliation can occur quickly and the whole shrub may turn brown.
New growth may appear, but repeated infections can weaken the roots and eventually kill the shrubs. This is particularly true for young shrubs and new transplants.
Boxwoods have long been a suburban favorite because they’re reliably evergreen, and, most important, deer resistant. They’re expensive and slow growers, so a widespread blight looks to be particularly worrisome.
Tonight, Daughtrey will be at the Chappaqua Library to present the fall talk in the Rocky Hills Lecture Series. It’s called “Global Gardening: Protecting Plants in the 21st Century.”
I’m going to the lecture tonight, and Daughtrey promises to bring new stats and general info about the boxwood blight, so stay tuned.