Elm: Bacterial wetwood (Slime flux)

categories: Elm Elm Diseases Ornamental trees Ornamentals

revision date: 2022-11-22 01:14

Scar on bark of elm tree caused by Elm bacterial wetwood (slime flux).
Elm bacterial wetwood (slime flux)
Photo by: R.S. Byther


Wetwood or slime flux is a bacterial infection common in elm and poplar. The infection causes production of large amounts of moisture in the wood of trunks or large branches. The rancid-smelling, often brownish fluid seeps through the bark and is associated with discolored wood and streaks on the bark. Occasionally other symptoms including wilting, yellowing, and dieback may be associated with wetwood in elms. Typically, however, wetwood is primarily an aesthetic concern.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Preventing injury to bark and wood may help prevent wetwood.
  • Installing plastic drain tubes to allow the fluid to drip on the ground rather than down the bark may improve the appearance of affected trees.
  • Affected branches can be removed for aesthetic reasons. Cut back to clean, healthy wood.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • None recommended