My shrubs are turning brown - Ask Extension
The leaves of my weigela have been getting brown spots then dying. I can't find any bugs or anything on it. My lilac is doing the same thing. Now my n...
Knowledgebase
My shrubs are turning brown #473832
Asked July 27, 2018, 2:46 PM EDT
The leaves of my weigela have been getting brown spots then dying. I can't find any bugs or anything on it. My lilac is doing the same thing. Now my new growth on my new dogwood is starting to get brown spots and curl up. Help!
Howard County Maryland
Expert Response
Don't worry too much.
In some ways, these symptoms are related, and in some ways not.
Some of that looks like leaf scorch damage. It has been an unusual year, with a long cool and wet spring, followed by very hot periods. The contrast can be stressful.
It is late enough in the year and most plants have more than enough leaves to deal with the stress without major problem.
Now the lilac photo looks like there may have been some digging or trenching nearby. Could that have cut some roots? That could absolutely show up in the leafy canopy. There is also some signs of powdery mildew affecting those leaves but that is so common as to be kind of normal for these shrubs in our area. How does the rest of the plant look?
Your new dogwood could be responding to the stress of planting.
Run through these pages to be sure you are giving it the best start you can:
http://extension.umd.edu/hgic/plants/trees-shrubs
One of the biggest mistakes that people make is to plant or mulch trees too deeply, which can kill them over time. Next on the list is failing to water them when we don't get about an inch of rain a week (for the first 18 months or so of establishment.)
Dogwoods are also prone to powdery mildew unless you got a variety that was bred with some resistance to this disease.
Here is a publication that covers some of the issues dogwoods can get in our area: http://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/TreesandShrubs/...
cm
In some ways, these symptoms are related, and in some ways not.
Some of that looks like leaf scorch damage. It has been an unusual year, with a long cool and wet spring, followed by very hot periods. The contrast can be stressful.
It is late enough in the year and most plants have more than enough leaves to deal with the stress without major problem.
Now the lilac photo looks like there may have been some digging or trenching nearby. Could that have cut some roots? That could absolutely show up in the leafy canopy. There is also some signs of powdery mildew affecting those leaves but that is so common as to be kind of normal for these shrubs in our area. How does the rest of the plant look?
Your new dogwood could be responding to the stress of planting.
Run through these pages to be sure you are giving it the best start you can:
http://extension.umd.edu/hgic/plants/trees-shrubs
One of the biggest mistakes that people make is to plant or mulch trees too deeply, which can kill them over time. Next on the list is failing to water them when we don't get about an inch of rain a week (for the first 18 months or so of establishment.)
Dogwoods are also prone to powdery mildew unless you got a variety that was bred with some resistance to this disease.
Here is a publication that covers some of the issues dogwoods can get in our area: http://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/TreesandShrubs/...
cm
