Knowledgebase

Ash tree #830331

Asked May 16, 2023, 11:19 AM EDT

I have used the app “picture it and it identifies the plant 4’-5’ high as an “ash tree”. We attached the photo. The tree seems to have some leaves which appear as it may be diseased (very curled and not fully opened) but we are not sure if this is normal or if it’s a disease. Any information you may be able to Provide to help us treat it (if needed) would be appreciated. Thank you!

Montgomery County Maryland

Expert Response

This does appear to be an ash, though we can't confirm that with certainty or ID it to the exact species of ash since several details in plant characteristics are used to ID plants, all of which are not visible here. Mature ash are becoming scarce in Maryland due to the accidental introduction to our area about two decades ago of an invasive beetle pest called Emerald Ash Borer. Sapling ash do continue to volunteer themselves in woodlands and some yards where seeds have blown-in, but we otherwise might not encourage the planting of an ash tree due to this beetle risk as it ages.

In either case, the damage pictured appears to be either viral or perhaps exposure to certain herbicide (weed killer) chemicals. Some herbicides are absorbed through roots while others can seep into bark or even just affect leaf growth by drifting on air currents as a mist during spraying. One common symptom of herbicide damage overlaps greatly with virus symptoms, which is distortion and the malformation of foliage or young green stems. Sometimes insect feeding causes distorted foliage, though usually not this drastically. Sap-feeding insects are one of the main culprits of moving plant viruses from one host to another, though, but these are largely natural processes that don't need management. (Plus, treating a symptomatic plant with insecticide, even if it was warranted, would be too late because the infection has already taken place and the insects are likely gone.)

Plant viruses are incurable but herbicide-induced oddities may be temporary and disappear over time as the plants grow out of the damage and the worst of the affected leaves fall off on their own. Time will tell which this is, though there is nothing you can do about either. Plant viruses, as common as they can be, aren't necessarily a threat to other garden plants nearby so you don't necessarily need to remove the sapling just for that reason. However, if it looks progressively worse, especially on all the new growth along the branch tips, it probably will weaken too much and die anyway, and in that case should be taken out. Don't prune just the distortions out as not only might that interfere with the tree's ideal branching structure but it won't cure a plant of virus if that is what is responsible for the symptoms. (You also don't want to contaminate the pruning tools unless you disinfect them afterwards by cleaning the blades with 70% rubbing alcohol. Avoid bleach as this might damage the metal.)

The less-likely cause for this particular damage is a gall. Galls are malformed plant tissues caused by a variety of organisms ranging from insects to mites to less-serious pathogens. They are somewhat akin to a tumor but they don't spread unless the organism that triggered the weird tissue growth are also feeding in more places on the plant over time. Shade trees of many kinds can develop all sorts of galls, many of which fairly unique, but none require intervention.

Miri

Loading ...