Why are my Boxwood’s Leaves Turning Brown? I have not done anything different to my front boxwood hedges, but this year they are not fully green and healthy looking. I tried fertilizer but that did not help, what is the problem?
There are several different problems that could be affecting the health of your Boxwoods. For a true and accurate diagnosis, we would have to send a Plant Health Care Technician to your property to inspect, but for now, we will take some time explaining the few issues that we see quite often.
Boxwood Blight is a fairly new fungal disease that was originally identified in North America in 2011. Signs of this include lesions or dark streaking on the stems, brown spotting on the leaves, and defoliation (leaves falling off the branches). These warning signs should not be ignored, because if left untreated, Boxwood Blight will completely kill your shrub and can rapidly spread across a group hedge.
When looking at your boxwood, if you notice the outside leaves appear yellowish in color and smaller than the green ones, as though they have shrunken, you probably have Leafminers. Leafminers are fairly noticeable to the common eye.
If you look closely you will see little yellowish-orange larvae. They tend to chew a tunnel through the top layer of the leaf, and then feed on the inside. As the larvae mature, they grow into reddish-yellow flies that will swarm around your boxwoods awaiting new growth.
As new growth develops, they lay their eggs on the healthy leaves and so the cycle continues and your leafminer problem exponentially gets worse.
Winter burn is a condition that occurs during cold winter months when the leafs of a plant have lost their water and the roots are completely frozen and unable to replenish. Despite the fact that boxwoods are a very hardy evergreen, they are particularly susceptible to winter burn.
Signs your boxwood is damaged because of winter burn include: the damaged portions of your shrub face the area the wind blows from (usually South or Southwest), foliage is damaged and dried out, and in severe cases, the stems are cracked.
In most cases, your Boxwoods can be revived and will bounce back to the hardy green shrubs you remember by next season. Unfortunately, in some instances, as with Boxwood Blight, if the disease has spread significantly, we may recommend removal of the infected plant.
The goal with Boxwoods and all your precious greens, is preventative care. This is the number one reason why we created our Plant Health Care Program. Rather than always getting the calls to fix the problem, we want to help ensure the problem never happens.
Spraying your shrubs with Horticultural Oils several times a year will help ward off diseases and insects. Also, ensuring your shrubs are nutritious and strong entering the winter season can greatly decrease the chances that cold weather will result in Winter Burn.
These services and more, are all part of our Plant Health Care Program. Custom designed to meet the needs of your property and keep your plants healthy all year round.
For more info or to sign up today, please call us at 914-725-0441.