why are all the trees diseased and/or dying? - Ask Extension
Everywhere I travel I see trees losing their bark (Virgin Islands, Hawaii, Boston) as well as here in the Baltimore area. Are the trees affected by t...
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why are all the trees diseased and/or dying? #930031
Asked April 29, 2026, 12:55 PM EDT
Everywhere I travel I see trees losing their bark (Virgin Islands, Hawaii, Boston) as well as here in the Baltimore area. Are the trees affected by the same condition, or are there multiple diseases killing our trees? Is there anything we can do to preserve some of the trees in our area?
Baltimore County Maryland
Expert Response
No, the same condition is not affecting trees in all of those widely-separated areas. However, stress from extreme weather could certainly be playing a role and predisposing the plants to other problems that cause more visible damage. For example, the drought Maryland has been experiencing (see the linked map) for the past two years is stressing trees and likely played a role in worse-than-average winter damage ("winterburn") on many evergreens and contributing to some branch dieback in deciduous plants this past season.
Additionally, the Maryland area had an overnight frost or freeze a week ago, which injured or killed any young leaves that were just emerging at the time. (Some plants were hit hard by this while others seemed unaffected. Many factors play a role in this, like nuances of how cold each spot got, how moisture-stressed any individual plant was, which species of plant it was and how tender the leaves were, etc.) We have received many questions about that frost/freeze damage on a wide variety of local plants.
Trees losing bark are suffering from a variety of conditions that are not necessarily related. The stage of wood decay that occurs with shedding bark is more advanced than recent damage, and what causes tree decline or death often starts months or years before symptoms become obvious. In urban and suburban areas, stress on the roots from limited growing space and compacted soil, extremes of moisture (saturated soils or very dry spells), air and soil pollution, exposure to lawn or agricultural herbicides, and reflected/radiated heat from pavement all contribute to shortening tree lifespans or predisposing them to a pest or disease outbreak.
Tree preservation takes many approaches, like continuing to plant young trees (native species in particular) that will take the place of mature canopy trees as they naturally decline. This natural process in woodlands is being interrupted by high deer populations that are eating saplings before they can grow out of reach. Invasive plants taking over habitat and out-competing tree seedlings and saplings, or climbing trees (like English Ivy) and contributing to their decline and death is another major problem in many regions. More extreme weather (heat waves, mild winter spells, soil flooding from heavy rainstorms, etc.) is an underlying issue as well.
Miri
Additionally, the Maryland area had an overnight frost or freeze a week ago, which injured or killed any young leaves that were just emerging at the time. (Some plants were hit hard by this while others seemed unaffected. Many factors play a role in this, like nuances of how cold each spot got, how moisture-stressed any individual plant was, which species of plant it was and how tender the leaves were, etc.) We have received many questions about that frost/freeze damage on a wide variety of local plants.
Trees losing bark are suffering from a variety of conditions that are not necessarily related. The stage of wood decay that occurs with shedding bark is more advanced than recent damage, and what causes tree decline or death often starts months or years before symptoms become obvious. In urban and suburban areas, stress on the roots from limited growing space and compacted soil, extremes of moisture (saturated soils or very dry spells), air and soil pollution, exposure to lawn or agricultural herbicides, and reflected/radiated heat from pavement all contribute to shortening tree lifespans or predisposing them to a pest or disease outbreak.
Tree preservation takes many approaches, like continuing to plant young trees (native species in particular) that will take the place of mature canopy trees as they naturally decline. This natural process in woodlands is being interrupted by high deer populations that are eating saplings before they can grow out of reach. Invasive plants taking over habitat and out-competing tree seedlings and saplings, or climbing trees (like English Ivy) and contributing to their decline and death is another major problem in many regions. More extreme weather (heat waves, mild winter spells, soil flooding from heavy rainstorms, etc.) is an underlying issue as well.
Miri
