Gardening: Progressing Plague
We have had trees and now azaleas that have either died or started appearing ill, moving sequentially along a straight line. First a mid-size cherry tree dropped it leaves and died in fall of 2015 (I recall it was a dry season). This year I noticed a very small tree had no leaves; I pulled on it and it just fell over, so clearly the roots were rotten. Now the first azalea along the line has lost all leaves (see photo, from right to left) and the one next in line has leaves that turned yellow and brown, and some fell off, leaving only the leaves on the ends (see close-up photo). Since this malady seems to travel in a line it makes me think there is some fungus or bacteria in the soil or something, but I don't know. I don't think there has been any pesticide application that would affect this area. Would you be able to offer some advice, and also suggest someone to work with? Thanks for your time.
Montgomery County Maryland
We have looked at your photos and consulted with the specialists: plant pathologist and entomologist, and there is fungus or bacteria or soil pathogen that would cause symptoms across these plants.
It is more likely a combination of factors, many of which are related to stressors like the drought you mentioned.
For the small tree you were able to 'just pull up', if it's a wet area a root rot is possible, but even more likely could be low root or bark damage from rodents like voles, who turn to woody plants in the winter for food.
The azalea could have had the same issue. These look old and established. Any dead, brittle wood can be trimmed away at any time. The ones showing buds and greenery on the branch tips should be left to wake up, sprout and bloom to see how full they are. Many types of azaleas drop a good portion of their leaves in the winter. All of them can be trimmed back after flowering if wanted.
The cherry tree could also have had more than one reason for succumbing. They are not long-lived trees in the landscape.
Without specific noticed symptoms, it's impossible to say what is actually going on but take a look at this link with many of the possibilities: https://extension.umd.edu/hgic/trees-and-shrubs/common-plant-and-pest-problems-trees-and-shrubs
If during the growing season you see particular issues- lesions on leaves, unusual growth etc. Feel free to contact us then for further assistance.
We do see ivy at the base of your plants. English Ivy can compete with and even smother other plants and is now considered invasive, and especially a nuisance in tracts of natural areas. You might consider getting rid of it. Here's more: https://www.na.fs.fed.us/fhp/invasive_plants/weeds/english_ivy.pdf
Thank you very much for your thoughtful response. I realize I don't have a lot of specific symptoms to provide, but what you said is helpful.
It turns out that one small tree in the area that I was thinking was dead has just started blooming; so the situation may not be quite as bad as I thought.