How to Manage Pests
Pests in Gardens and Landscapes
Wetwood or Slime flux
Wetwood is caused by several species of bacteria; yeast organisms may also be involved. Wetwood is especially
common in elm and poplar, but affects many other plants including box elder, hemlock, magnolia, maple,
and oak. Affected trees have stained areas of wood that exude fluid. Usually trees about 10 years of age
or older exhibit symptoms. Foliage wilt and branch dieback can occur on severely infected trees. Although
it can be unsightly, affected wood may be as strong as healthy wood.
Prevent wetwood bacteria and yeasts from infecting trees by avoiding injuries to bark and wood.
Control wetwood infections when they are small by opening wounds so they are exposed to the air and liquids
do not accumulate; avoid making large wounds. To reduce the spread of bacteria and yeasts in an infected
tree, drill a 0.25-inch hole several inches long until fluid begins flowing, then install a copper tube
to drain excess fluid and release the pressure of gasses that form in infected wood. Don't insert the
tube so far into the hole that the inside end becomes plugged. Leave the outside end of the tube protruding
so that liquid drains away from the infected bark area. Check the tube opening regularly and clear it
if it becomes plugged. Do not weaken the tree's structure by drilling drain holes at branch crotches.
infection causes stained wood