Tree dropping leaves - Ask Extension
I noticed this tree dropping many leaflets in the last day or two. The leaves have many dark spots mostly along the upper surface.
What is causing...
Knowledgebase
Tree dropping leaves #873244
Asked June 15, 2024, 3:12 PM EDT
I noticed this tree dropping many leaflets in the last day or two. The leaves have many dark spots mostly along the upper surface.
What is causing this? And can I do anything to help the tree?
It might be black walnut, but I'm not certain of ID. The bark is different than nearby black walnut trees though it has the remnants of English Ivy going up the tree.
It's located a few feet above the bottom of a drainage ditch that sometimes has standing water. On the slope immediately above the tree, the previous owner covered the ground in landscape fabric/plastic. With current mostly dry conditions, I worry that the plastic prevents water from getting to the roots on the upslope side.
Thank you.
Baltimore County Maryland
Expert Response
The foliage pictured looks like hickory (genus Carya), which is a relative of walnut, though the foliage is distinct enough between them to tell them apart. You are correct that long-term use of landscape fabric might interfere with root health, depriving them of enough moisture and gas exchange (oxygen levels in the soil) and potentially leading to stress or dieback. Standing water in the root zone can also impact root health, and may kill sensitive roots if the tree is a species intolerant of temporary flooding. (Several species of hickory grow in Maryland -- see linked page above -- with varying wetness tolerances, and we can't ID the sample pictured to species. You can use the Virginia Tech tree ID key if you'd like to try, though.)
The leaf spot pictured might be a minor fungal disease, which is fairly common on a wide variety of trees by this point in the growing season. It is probably unrelated to the leaf drop, since leaf spot infections rarely affect the overall health of a tree, though we can't be certain. If the tree is on your property, you could ask a certified arborist to evaluate it in person. Arborists can't diagnose every condition with certainty if it's been ongoing for a while (say, if the telltale symptoms have been obscured) or if it requires a laboratory sample, but they can assess the tree's overall health and look for typical sources of stress that might be able to be alleviated. Arborists also can't cure or treat every condition to reverse its impacts (sometimes, by the time symptoms manifest, it's too late), though not every ailment is serious or fatal to a tree.
Miri
The leaf spot pictured might be a minor fungal disease, which is fairly common on a wide variety of trees by this point in the growing season. It is probably unrelated to the leaf drop, since leaf spot infections rarely affect the overall health of a tree, though we can't be certain. If the tree is on your property, you could ask a certified arborist to evaluate it in person. Arborists can't diagnose every condition with certainty if it's been ongoing for a while (say, if the telltale symptoms have been obscured) or if it requires a laboratory sample, but they can assess the tree's overall health and look for typical sources of stress that might be able to be alleviated. Arborists also can't cure or treat every condition to reverse its impacts (sometimes, by the time symptoms manifest, it's too late), though not every ailment is serious or fatal to a tree.
Miri
