Pests and the garden – the bane of boxwood blight

As if the heat and humidity weren’t enough for the garden, as we at the Morano Group have discussed in two previous posts, we now have the challenge of boxwood blight, courtesy of the fast-flying, invasive box tree moth.

The moth (Cydalima perspectalis) spends its life cycle (from black and lime caterpillar to mature insect, with a white body and brown head and stomach) on boxwood, a multimillion-dollar ornamental staple of the American garden as hedges, bushes and topiaries. The moth can defoliate and, if not caught early, destroy boxwood, so it’s important to be vigilant against this hardy pest, which made its way from Europe to Western Asia and North Africa, arriving in Canada and Niagara County, New York, in 2021.

Once plants are infected, you’re going to have to uproot them, collecting all the leaf material. Then your choices are to bury the stuff at least 2 feet deep, burn it or double bag it for landfill. In any event, you won’t be able to plant boxwood in its former home for six years as that’s how long the spores can last.

How to avoid this garden crisis?
Boxwood Blight

Look for box tree moth-resistant boxwood, being careful where you buy it.
Plant your new boxwood away from existing boxwood, keeping an eye on both.
Use fungicide prophylactically and cautiously, knowing it’s no help against infected plants.
Keep your plants well-spaced and judiciously watered, as overwatering and crowding can abet the blight.
With retailers, including garden centers and nurseries, already looking to the holiday season, plan on keeping your holiday boxwood decorations away from your existing boxwood. Send the decorations to the landfill when the season is over. Never compost boxwood decorations.

If you find an insect that you suspect is the box tree moth, contact your local Extension Office or State Plant Regulatory official to have the specimen identified. To locate an Extension specialist near you, visit the USDA website at www.nifa.usda.gov/Extension. A directory of State Plant Regulatory officials is available on the National Plant Board website at www.nationalplantboard.org/ membership.

As always, we at the Morano Group stand ready to assist you.