Yellow leaves on holly shrubs - Ask Extension
We planted holly shrubs alongside our driveway two years ago. They seemed to be doing fine. I fertilized them (with stakes and some Hollytone) las...
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Yellow leaves on holly shrubs #557090
Asked April 30, 2019, 10:42 AM EDT
We planted holly shrubs alongside our driveway two years ago. They seemed to be doing fine. I fertilized them (with stakes and some Hollytone) last month. Their leaves are now turning yellow. Too much fertilizer? Not enough water? PH issue? Welcome your guidance on how to take care of them. (See pics)
Montgomery County Maryland
Expert Response
These look like Japanese holly (Ilex crenata). It is normal for hollies to have some yellowing leaves that drop off this time of year. This happens on the older leaves. Please see the following information on our website,
http://extension.umd.edu/hgic/topics/normal-leaf-shedding
Japanese hollies can be finicky though. They do not like heavy, clay soil that remains wet and are prone to root rot. This usually presents itself as a slow decline of the shrubs. With branches turning brown and dying. It might be a good idea to test the soil in the bed to check the pH especially if this is a newer home. The next time you fertilize do not use stakes or spikes. They concentrate the fertilizer in one area and can damage roots. It is not good to give them too much fertilizer either. Once a year is plenty. If they are growing in fertile soil it may not be necessary at all.
The following is information about soil testing.
http://extension.umd.edu/hgic/topics/soil-testing
Deb
http://extension.umd.edu/hgic/topics/normal-leaf-shedding
Japanese hollies can be finicky though. They do not like heavy, clay soil that remains wet and are prone to root rot. This usually presents itself as a slow decline of the shrubs. With branches turning brown and dying. It might be a good idea to test the soil in the bed to check the pH especially if this is a newer home. The next time you fertilize do not use stakes or spikes. They concentrate the fertilizer in one area and can damage roots. It is not good to give them too much fertilizer either. Once a year is plenty. If they are growing in fertile soil it may not be necessary at all.
The following is information about soil testing.
http://extension.umd.edu/hgic/topics/soil-testing
Deb
Thank you for this insightful guidance. Based on your recommendation, I tested the PH of the soil surrounding our holly shrubs. It averaged at 7.0. I read that hollies grow best in a soil ph of 5.5. So what do I do now. Spray the hollies. Add chemicals to the soil. What do you recommend?
Did you send your soil to one of the soil testing labs that were recommended or did you use a home tester? Sometimes home testers are not reliable. But a pH of 7.0 is a bit high. They do best in soil with a pH of 5.5 - 6.5. If the organic matter is high in the soil it may not be necessary to do anything. But you can add sulfur, you can find 4 - 5 lb bags of it in a garden center, to the soil. Pull the mulch away and gently scratch it into the soil around the shrubs, water it in, or wait for the rain to do it. In general, to lower the pH to 5.5 you need about 2.5 lbs of sulfur per 100 sq ft. Most likely there will be instructions on the bag on how to use it around shrubs.
Deb
Deb
