Flowering plum leaf drop

[Joe]

I've got some flowering plum trees (purple leaves) that every year start to defoliate...sometimes about half, sometimes more. The tree does get some of its leaves back at the tips and comes back great in the spring again. I've taken a leaf around and the opinions vary (too much water, not enough water, fertilizer, no fertilizer, no idea). The leaf seems to get brown and dry, but not wilt. Anything planted nearby (within its root zone) has plenty of water and has no problem throughout the growing season. I don't find any visible parasites. Any ideas would be greatly appreciated!

[Newt]

Hi Joe,

I think you answered your own question. Too much water. How old are the trees?

Anything planted nearby (within its root zone) has plenty of water...

Purple leaf plum aka Cherry plum - Prunus cerasifera 'Atropurpurea', is a short lived tree prone to many insect pests and diseases. Look here under 'Pest Problems' on the right for some of the pests this tree is prone to.
https://www.co.chesterfield.va.us/HumanServices/Extensio...s/PurpleleafPlum.asp

Newt

[Joe]

I couldn't open your link, Newt. So you think too much water? The other plants in the area aren't having trouble, though. There are three trees: two are 2 years in the ground (from the nursery) and 1 is about 5 years in the ground...all exhibiting the same trouble.

[Newt]

Hi Joe,

Sorry about that. Try this one. Look at the last page for pest and disease info.
https://hort.ifas.ufl.edu/trees/PRUCERC.pdf
https://image.fs.uidaho.edu/vide/famly114.htm#Prunus%20cerasifera

I do think it's overwatering as you are watering the plants often and overwatering the trees. Here's info on tree roots.
https://edis.ifas.ufl.edu/MG089
https://www.mortonarb.org/research/treeroots.html
https://www.ext.colostate.edu/pubs/Garden/02926.html
https://www.treesaregood.com/treecare/mulching.asp

Newt

[Joe]

Thanks, Newt...I'm going to start by adjusting the watering.

[Newt]

Joe, you are very welcome! I always recommend planting drought tolerant plants if planting under a tree. Epimedium is one that comes to mind.

Good luck,
Newt

[The Helpful Gardener]

Genus Prunus (plums, cherries, etc.) can get LOTS of fungal diseases, so rule those out as well...

HG