Dutch Elm Disease

You don't know what you've got until it's gone...

What is Dutch Elm Disease?

Dutch Elm Disease (DED) is a fatal disease of Elm trees, caused by the fungus Ophiostoma novo-ulmi. 

What types of trees are at risk from DED?

DED infects most species of Elm in North America, including the widespread American Elm and its cultivars. 

What is a 'cultivar?'

A 'cultivar' is a variety of plant that has been selectively bred for specific characteristics. Some cultivars of the American Elm have shown to have tolerance/resistance to Dutch Elm Disease.

What are the observable symptoms of a DED infected tree?

The symptom of DED to look out for is the wilting and dieback of foliage in the growing season. The leaves curl, turn brown rapidly and some will stay attached to the tree. You may see sawdust at the base of your tree also in spring and fall from nesting beetles.

What do I do if I see these symptoms?

Contact us to evaluate your tree. There are other fungal infections that can mimic DED, and before removing a tree, a laboratory test should be performed to determine that it is Dutch Elm Disease.

Is there a cure for the disease?

Unfortunately not. There are treatments available and strategies to protect your tree from Dutch Elm Disease, which is recommended if you don't want to lose your tree.

How is DED spread?

The Elm Bark Beetle spreads the disease by flying to other trees. Trees in close proximity to each other can spread the disease through root grafting. 

What can I do to help control DED?

Beetles are attracted to stressed trees, so keeping yours as healthy as possible will reduce the chance of the insect being tempted toward it. Treat valuable trees to keep the species alive, and apply Basal Spray annually to help reduce the population of the beetle. Have your tree deadwood pruned when needed and maintain good tree health. Storage and transportation of Elm wood is also prohibited.

What can I do to prevent tree stress?

A tree will have more stress living in an urban setting, than one living in its natural environment. Trees need good soil fertility to be healthy, and will be thankful for good soil structure and regular watering in the growing season. Adequate sun is essential and appropriate pruning when needed helps too. A tree might need some health care treatments to alleviate any existing ailments, but a healthy tree can often defend itself against urban challenges once its basic needs have been met.