Can you please help, identifying and remedy of this disease on our tree? Thanks! - Ask Extension
Good evening, we need your help in identifying and possible remedy for this disease. We appreciate your help with this. Thanks!
Knowledgebase
Can you please help, identifying and remedy of this disease on our tree? Thanks! #868794
Asked May 16, 2024, 7:02 PM EDT
Good evening, we need your help in identifying and possible remedy for this disease. We appreciate your help with this. Thanks!
Howard County Maryland
Expert Response
The growths pictured are lichen, a harmless organism that does not damage trees. If abundant, it can indicate that the bark it's growing on is receiving more moisture and/or light from gaps in the canopy, such as from leaf loss on declining branches, but the lichen is not the cause of decline. If there are other symptoms you can share, or more information about what species of tree this is and how/when decline began, we can try to determine what might be going on and if intervention is possible. If the tree happens to be leafless already, it probably cannot be salvaged, but we'd need to see more of its overall appearance and where it is growing.
Miri
Miri
Good morning,
Thank you for your response, it is Bradford pear tree, planted in 2000. Last spring (2023) was year, we noticed less and delayed leaves on this tree, we contacted a local nursery and were asked to remove any grass near trunk as weed and feed might be affecting it. We put a 3.5' X 3.5' frame around it (after removing any grass) and put some fertilizer spikes (for trees). This spring same problem, there are very few if any leaves are visible.
Ketan
Hello Ketan,
Without an image of the entire tree to see how badly the leaf loss is affecting it (or if there is an infection present), it's hard to say if it's salvageable. If weed'n'feed is applied yearly to the lawn, and if the tree is mostly surrounded by lawn, then its exposure is much greater than just a 3- to 4-foot zone around the trunk. For a tree nearly 25 years old, its roots will extend far out from the trunk, well past the canopy edges, so if lawn occupies much of that area, the dosage of herbicide exposure (if that is what is contributing to dieback) is large enough that it could be causing widespread canopy decline. Some herbicide ingredients are more damaging to tree roots than others; dicamba, for instance, is one of them that can cause significant injury.
Fertilizer is not recommended for a plant in decline, as it has the potential to worsen the situation and the roots, if they are ailing already, will not be able to make use of the supplemental nutrients. Plus, it's unlikely that the soil itself is deficient enough in most needed nutrients such that fertilizer will make much of a difference. While the application you already made can't be undone, for the future, we suggest that a plant that is struggling not be fertilized unless a distinct nutrient deficiency is the only cause of discolored leaves or poor growth.
Bradford pears and other Callery pear cultivars are invasive trees, having spread widely in Maryland natural areas, and we discourage gardeners from growing them. Therefore, if this tree has enough decline that recovery is unlikely, we recommend removing it and replacing it with a native (or at least non-invasive) species. Since it sounds like there are hardly any leaves on the tree, it is definitely too weak to expect recovery, nor is it treatable, though you could always hire a certified arborist to consult who can assess the tree in person and try to determine what began the decline. It almost certainly wasn't a canopy infection (though a less-serious twig infection is still possible as an overlapping issue), but likely began either in the root zone or as damage (from weather, insects, injury, etc.) to the trunk.
Miri
Without an image of the entire tree to see how badly the leaf loss is affecting it (or if there is an infection present), it's hard to say if it's salvageable. If weed'n'feed is applied yearly to the lawn, and if the tree is mostly surrounded by lawn, then its exposure is much greater than just a 3- to 4-foot zone around the trunk. For a tree nearly 25 years old, its roots will extend far out from the trunk, well past the canopy edges, so if lawn occupies much of that area, the dosage of herbicide exposure (if that is what is contributing to dieback) is large enough that it could be causing widespread canopy decline. Some herbicide ingredients are more damaging to tree roots than others; dicamba, for instance, is one of them that can cause significant injury.
Fertilizer is not recommended for a plant in decline, as it has the potential to worsen the situation and the roots, if they are ailing already, will not be able to make use of the supplemental nutrients. Plus, it's unlikely that the soil itself is deficient enough in most needed nutrients such that fertilizer will make much of a difference. While the application you already made can't be undone, for the future, we suggest that a plant that is struggling not be fertilized unless a distinct nutrient deficiency is the only cause of discolored leaves or poor growth.
Bradford pears and other Callery pear cultivars are invasive trees, having spread widely in Maryland natural areas, and we discourage gardeners from growing them. Therefore, if this tree has enough decline that recovery is unlikely, we recommend removing it and replacing it with a native (or at least non-invasive) species. Since it sounds like there are hardly any leaves on the tree, it is definitely too weak to expect recovery, nor is it treatable, though you could always hire a certified arborist to consult who can assess the tree in person and try to determine what began the decline. It almost certainly wasn't a canopy infection (though a less-serious twig infection is still possible as an overlapping issue), but likely began either in the root zone or as damage (from weather, insects, injury, etc.) to the trunk.
Miri
