Dutch Elm Disease resistance - how safe?

Asked March 7, 2019, 9:40 AM EST

Is it advisable to plant a resistant elm where a diseased elm was removed? We are removing a large elm that got DED last year. The ideal replacement for that spot is an elm, but I'm not sure if the "resistant" elm cultivars (e.g.: ‘Valley Forge’) are safe to plant in the same ground where the disease was/is present. We could try another species but I really like the elm for that spot.

Washtenaw County Michigan dutch elm disease replanting after tree died

4 Responses

The disease does not linger in the soil. It is carried to a tree by an elm bark beetle or through root grafts with other elms that have the disease. So you can replant in the area. If you kept the logs for firewood from the dead elm, this could be a source of elm bark beetles this spring when they emerge from logs. If you kept logs make sure they are covered with a tarp to the ground to prevent beetles from emerging through the first summer. Even resistant American elms can get Dutch Elm Disease but chances are increased by leaving logs from trees that died last year near where the new tree is planted. Logs should either be removed, debarked, or covered completely for first season.

The disease does not linger in the soil. It is carried to a tree by an elm bark beetle or through root grafts with other elms that have the disease. So you can replant in the area. If you kept the logs for firewood from the dead elm, this could be a source of elm bark beetles this spring when they emerge from logs. If you kept logs make sure they are covered with a tarp to the ground to prevent beetles from emerging through the first summer. Even resistant American elms can get Dutch Elm Disease but chances are increased by leaving logs from trees that died last year near where the new tree is planted. Logs should either be removed, debarked, or covered completely for first season.

Thank you. The diseased elm is gone - removed and chipped. However, we have many native elms in our wooded neighborhood, with one dying every 3-5 years, so the disease will never be far away. In that respect "resistant but not immune" is a concern. Would a Zelkova be safer?

There have been some great elm introductions in the search for a resistant elm that has the beautiful canopy of the American elm. Valley Forge is listed by the Morton Arboretum as having excellent resistance to Dutch elm disease. Of course resistance does not mean a disease cannot happen. The Morton Arboretum has a great description of the resistant American elm cultivars and the other elms that have been breed using Asian and European elm. See the following: https://www.mortonarb.org/trees-plants/tree-plant-descriptions/elm-cultivars
Zelkova have the vase shaped growth of the American elm but not nearly as graceful an appearance. It is also resistance to DED but is susceptible to canker disease.