Boxwood blight, also known as box blight and boxwood leaf-drop, has become increasingly concerning for the northeast region in recent decades. Originating in Europe, that sneaky stowaway has made its way to our eastern seaboard. The current research shows that boxwood blight seems to be spread not only by splashing rain, but also by having infected trees transplanted from nurseries. Symptoms will appear on leaves and shoots. Although there are many ways to prevent blight and treat your boxwoods, ultimately there is no cure and blight can be fatal in younger trees.
Originally noticed in Europe, boxwood blight has journeyed across the Atlantic to the US. Winding its way up the east coast, Connecticut has recently seen a large outbreak of blight across nurseries, botanical centers, and homes. Infected trees are being purchased from nurseries and suppliers before the symptoms have become apparent. This furthers the demand for reputable and reliable wholesalers and nurseries willing to scrutinize their stock. The buyer is also responsible for inspecting and, if must, refusing ANY suspicious or questionable product.
Unfortunately, symptoms of blight don’t always appear right away. This furthers the spread of infection as suppliers are shipping visually “healthy” plants. The buyer then gets a not-so-welcome “Trojan horse” when spots begin to appear. The circular spots will be varying degrees of light to dark brown, with the darkest shade around the border. These lesions will initially appear as single spots, but will eventually coalesce (merge). The foliage will quickly begin to yellow as leaves start to fall. Stems will present with dark brown or black lesions. It is not uncommon for these lesions to have a diamond-like pattern. And although the plants will attempt regrowth, the strain on the root system will often be fatal in young plants. Due to the nature of close-growing boxwoods not only in their natural setting, but in tight nursery and wholesaler spaces, where pot-pot infection is common, the disease is spreading rapidly. The disease can remain active in fallen foliage for up to 5 years! The sticky spores are also spread by contaminated tools, clothing, animals and even splashing rain, thriving not only in naturally warm and humid conditions but in nurseries and greenhouses as well.
Preventing boxwood blight is difficult and can be rather expensive. Educated growers will begin with widely spaced pots to reduce the instance of contaminated foliage falling too close to healthy plants. Fungicides can prevent and treat blight however, there is no cure. Recent research into developing resistant cultivars may seem promising but none are immune to the disease, and may prove to be a double edged sword. Their resistance may produce a delayed or subtle onset of symptoms, causing sellers to unknowingly ship infected plants across the country. Virginia Tech has also begun to develop different ways to reduce contamination. One possible method of suppression may be found in mulch. The coverage it provides may help reduce rain-splash, air current, and animal transmission. Multiple universities and research teams are also trying to develop a more efficacious fungicide.
Consider these helpful hints when working with boxwoods:
- Disinfect all tools and equipment using Lysol, rubbing alcohol, or bleach.
- ANY plants with a suspected infection must be bagged immediately to prevent spores from spreading during the removal.
- Thoroughly rinse footwear, or wear disposable booties, when working and moving around boxwoods, even if infection is not confirmed.
- Do NOT compost the infected plants as spores remain viable for years.
- Call us with ANY questions or concerns. Our licensed Arborists are here to help!
And as always, we here at Fox Tree Service are here to help you keep your property healthy, happy and hearty.