Gummosis on cherry tree and other plants dying near it

Asked June 25, 2020, 9:45 AM EDT

I have a very young cherry tree that has gummosis and seems to be dying -- no evident insect damage, and it's within a perennial bed where it couldn't get knocked by a mower or anything. Nearby, an old rose we transplanted is also dying, and a weigela is also dying -- thought you couldn't kill those. I've attached pics of the cherry and the weigela. Any ideas for an immediate treatment would be much appreciated. I created this garden in just the past year, adding a significant amount of manure to what is a thick, stinky blue clay layer overtop of sand. Appreciate any help.

Calvert County Maryland

1 Response

Hi - It is unfortunate to see you are having problems with your new tree. Yes, we see the gummosis (a symptom of borer damage) and also noticed there are several branches with signs of black knot, a fungal disease.
Chemical controls are not effective for this and generally we recommend pruning out the affected areas. However, given the extent of these problems in such a young tree, our recommendation would be to replace the tree with a healthy one.

It sounds and looks like you are dealing with challenging soil conditions. Describing the soil as "stinky" suggests it is anaerobic -- lacking oxygen due to saturation and heavy clay. We generally recommend using compost to amend clay soil, which can will help to improve its structure, porosity, etc.
Weigela likes to be in well-drained soil, so the heavy, wet soil is most likely a factor in why it is struggling to establish.

We note in your photos that some of your plants -- especially the grasses -- are doing quite well in the soil conditions you have. I would suggest exploring more grasses and types of plants that are native to the Maryland coastal plain conditions. This site (and the native plants guide listed on it) is an excellent resource for finding Maryland native plants (including those specifically adapted to the coastal plain region).