Browning on leaves of new boxwood shrubs - Ask Extension
About a month ago we planted 3 common boxwoods in our front bed. We've been noticing some browning on a few of the leaves and wanted to see if you mig...
Knowledgebase
Browning on leaves of new boxwood shrubs #913997
Asked August 14, 2025, 11:27 AM EDT
About a month ago we planted 3 common boxwoods in our front bed. We've been noticing some browning on a few of the leaves and wanted to see if you might know what it is and what we should do to keep these plants healthy. We have a timer and a soaker hose to water them every morning before the sun comes up. The house faces north and they get a decent amount of sunlight.
Charles County Maryland
Expert Response
Daily watering should not be needed, so you can reschedule the soaker hose to run roughly once a week (less with enough rain), though even then, it's best to only run the system manually once you determine the soil had dried out enough to need watering. While the current leaf symptoms are very minor and not likely tied to root rot, over-watering can cause root death and corresponding branch dieback, and may develop symptoms too late to do anything about it. (There is no fungicide cure for root rot.)
Boxwood roots grow more shallowly than many shrubs, and do not thrive when kept consistently wet, so make sure the soil drains well so the roots can get enough oxygen to stay healthy. (The more saturated soil stays, the less oxygen is available in the soil pore spaces for roots to access.) Mulch can help reduce evaporation after watering, and it will keep the soil cooler as well, but use only about an inch or two of mulch depth to avoid depriving roots of aeration. (Less sensitive shrubs can handle 2-3 inches of mulch depth.) To determine when to water, feel the soil about five inches deep near the roots and only water the root zone thoroughly once the soil becomes somewhat dry to the touch at that depth. Even if it doesn't cause root rot, frequent waterings can force roots to grow more shallowly, which puts them at greater risk for drought stress later, more exposure to summer heat and winter cold, and damage if any digging needs to occur (either for planting annual companion plants or to remove weeds).
The pictured leaf spotting and browning looks very minor and not concerning; it could be a type of leaf spot disease, but it does not look like one of the more damaging ailments that boxwood can be vulnerable to. (Common Boxwood, Buxus sempervirens, is overall more susceptible to the significant pest or disease issues of boxwoods than other species, like Buxus microphylla and Buxus japonica.) Minor leaf spot diseases are very common on a variety of perennials, shrubs, and trees by the end of summer, and they do not affect plant health enough to warrant fungicide use. (Nor would the application of a fungicide be able to cure existing infections.)
The plants pictured look quite healthy so far. Avoid shearing them as they mature and they will be more resistant to infections and pest outbreaks (over-pruned boxwoods are more prone to problems); in fact, other than small adjustments you may want to make as they get larger with age, in order to tweak their shape or height as desired, you won't need to do much pruning at all, and they will generally be healthier for it if trimming is kept to a minimum.
Miri
Boxwood roots grow more shallowly than many shrubs, and do not thrive when kept consistently wet, so make sure the soil drains well so the roots can get enough oxygen to stay healthy. (The more saturated soil stays, the less oxygen is available in the soil pore spaces for roots to access.) Mulch can help reduce evaporation after watering, and it will keep the soil cooler as well, but use only about an inch or two of mulch depth to avoid depriving roots of aeration. (Less sensitive shrubs can handle 2-3 inches of mulch depth.) To determine when to water, feel the soil about five inches deep near the roots and only water the root zone thoroughly once the soil becomes somewhat dry to the touch at that depth. Even if it doesn't cause root rot, frequent waterings can force roots to grow more shallowly, which puts them at greater risk for drought stress later, more exposure to summer heat and winter cold, and damage if any digging needs to occur (either for planting annual companion plants or to remove weeds).
The pictured leaf spotting and browning looks very minor and not concerning; it could be a type of leaf spot disease, but it does not look like one of the more damaging ailments that boxwood can be vulnerable to. (Common Boxwood, Buxus sempervirens, is overall more susceptible to the significant pest or disease issues of boxwoods than other species, like Buxus microphylla and Buxus japonica.) Minor leaf spot diseases are very common on a variety of perennials, shrubs, and trees by the end of summer, and they do not affect plant health enough to warrant fungicide use. (Nor would the application of a fungicide be able to cure existing infections.)
The plants pictured look quite healthy so far. Avoid shearing them as they mature and they will be more resistant to infections and pest outbreaks (over-pruned boxwoods are more prone to problems); in fact, other than small adjustments you may want to make as they get larger with age, in order to tweak their shape or height as desired, you won't need to do much pruning at all, and they will generally be healthier for it if trimming is kept to a minimum.
Miri
