Cut-leaf Elder

(Question)

I have a three year old Cutleaf Elder which has been doing wonderfully until about three weeks ago. The top leaves suddenly turned brown then wilted, I removed them and thought that it may be a lack of water so I watered a little more than normal. Then last week the remainder of the Elder’s leaves turned brown and wilted so now the shrub is bare of leaves and is looking very sad. I have scratched the bark to see if the branches are still alive and the scratch marks are showing green so I hope there may be some hope that the shrub will come back.

Can you tell me what you may suspect is the problem as I believe Elder’s are fairly hardy and can with stand some drought. My neighbors have a birch tree and a Chestnut tree that both look over my yard, I thought I would mention this in case this information was of some use. Thank you for your time and advice.

(Answer)

 

Your plant could be suffering from verticillium wilt. There are two different fungi that cause this disease and unfortunately they are soil borne fungi that have no known cure. Elder is one of the species that is susceptible to verticillium.

According to the University of Minnesota/Extension website symptoms caused by verticillium develop anytime during the growing season, but are most apt to appear in July and August. In some cases the symptoms may be more severe during or following cool weather. Symptoms appear chronically, or they may be acute and often lethal. Chronic symptoms include small, yellow foliage, leaf scorch (marginal browning), slow growth, abnormally heavy seed crops and dieback of shoots and branches. Often, the foliage on one or more branches wilts suddenly. Acute symptoms include leaf curling, drying, an abnormal red or yellow color of leaves or areas between leaf veins, partial defoliation, wilting and branch dieback. Often one branch or one side or sector of the plant is affected. Recurrence of wilt in ensuing years is unpredictable, as is its severity. In its lethal form, verticillium wilt will cause a sudden and total collapse of the plant. You might want to contact a university extension service to test the plant and confirm this diagnosis.

You could try to keep the plant well fertilized with compost or organic matter and keep it well watered. This will help to ensure that there are no additional stressors and the plant might be able to fight off the disease. If you find that you are pruning your shrub again next year to remove dead material, make sure you disinfect your pruning shears with rubbing alcohol or a 10% solution of bleach and water. Any wood should be removed and destroyed and not chipped or composted as you can spread the disease to other areas of your garden.

If your plant does succumb, you would be wise to plant a verticillium-resistant plant – such as hawthorne, hickory, poplar, ginkgo, mountain ash or mulberry — in that area since the fungal spores will remain in the soil for up to 15 years after you remove your elder.