Holly tree turning brown - Ask Extension
I have a holly tree, at least 25 years old. It’s typically green leaves are uniformly turning brown. Please see the attached photos. Your thoughts o...
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Holly tree turning brown #894247
Asked March 12, 2025, 3:55 PM EDT
I have a holly tree, at least 25 years old. It’s typically green leaves are uniformly turning brown. Please see the attached photos. Your thoughts on the cause of the transition would be appreciated.
Anne Arundel County Maryland
Expert Response
Do you know what species of holly it is? That will help us narrow-down a diagnosis, since their vulnerabilities to various infections or other problems can vary considerably. Although some holly species do have spineless leaves, the pictured plant doesn't quite look like a holly (it looks more like a privet), though it's hard to see clearly). The leaves appear to be attached to the stem opposite of each other (a feature of privets), not alternating as hollies do.
If this is environmental damage, it's probably winterburn, though usually that's seen on the youngest growth most exposed to the wind or winter sun. This is a type of desiccation damage, and it occurs when dry winter air and frozen soil moisture prevent the water evaporating out of evergreen leaves from being replaced, which causes the tissues to dry out and die. Winterburn damage shows up most prominently in early spring, even if it actually occurred weeks before. Damaged leaves will be shed, usually around the time the affected plant is ready to produce new growth for the season.
This also resembles damage from commonplace fungal infections, such as Botryosphaeria canker or Rhizoctonia blight, both of which have a fairly wide host plant range and can affect holly and other broadleaf evergreens. The former tends to take advantage of plants stressed by high heat and drought, while the latter tends to take advantage of plants with poor air circulation when the leaves are wet (after irrigation or a rainy spell, for example). Neither is treatable with fungicide once symptoms manifest, but the branches with brown leaves would need to be pruned off. (Those with entirely brown growth...those with only brown leaves toward the base/interior of the plant might just shed those leaves and not get any worse.) Was the plant monitored for watering needs last summer and autumn? If not, drought stress may be playing a large role in its current condition.
For now, since fungicide use would not be of any benefit, just keep an eye on the plant's root moisture and water as needed. The brown leaves will fall off soon, and if new symptoms appear, or new growth seems to be dying back, feel free to share more photos and we can try to narrow-down the diagnosis.
Miri
If this is environmental damage, it's probably winterburn, though usually that's seen on the youngest growth most exposed to the wind or winter sun. This is a type of desiccation damage, and it occurs when dry winter air and frozen soil moisture prevent the water evaporating out of evergreen leaves from being replaced, which causes the tissues to dry out and die. Winterburn damage shows up most prominently in early spring, even if it actually occurred weeks before. Damaged leaves will be shed, usually around the time the affected plant is ready to produce new growth for the season.
This also resembles damage from commonplace fungal infections, such as Botryosphaeria canker or Rhizoctonia blight, both of which have a fairly wide host plant range and can affect holly and other broadleaf evergreens. The former tends to take advantage of plants stressed by high heat and drought, while the latter tends to take advantage of plants with poor air circulation when the leaves are wet (after irrigation or a rainy spell, for example). Neither is treatable with fungicide once symptoms manifest, but the branches with brown leaves would need to be pruned off. (Those with entirely brown growth...those with only brown leaves toward the base/interior of the plant might just shed those leaves and not get any worse.) Was the plant monitored for watering needs last summer and autumn? If not, drought stress may be playing a large role in its current condition.
For now, since fungicide use would not be of any benefit, just keep an eye on the plant's root moisture and water as needed. The brown leaves will fall off soon, and if new symptoms appear, or new growth seems to be dying back, feel free to share more photos and we can try to narrow-down the diagnosis.
Miri
