QuestionThis is concerning damage to a very large, mature whiteoak on my property. Description: An area starting at ground level approx 1 foot wide and proceding up the trung 14"-18" without bark with what appears to be dead, darkened wood exposed. This area seems to have been attacked by stump borer beetles as there are multiple 1/2" wide holes bored into the wood. Not sure if this is related to the original wound in the tree. There continues to be sawdust like material at the edges of the wound and the base.
I have watched this proceed since last summer's drought and the wounded area continues to show activity (The sawdust like collections on the ground and bark edges). There are a couple of darkened areas on other places of the trunk at waist and head level but don't seem to be near as bad ... just more like sap oozing from wounds. The rest of this majestic tree seems very healthy but I suspect it might not stay so. Nice full canopy. Side note, the yellow jackets are feasting either on the sap or on the culprit critters causing the damage. There are always half a dozen or so swarming and crawling around the "wound".
Will this beautiful tree succumb and is there anything to combat the pests? What is the tree's (and mine) problem(s).
AnswerSure sounds like slime flux.
The oozing is called "slime flux" and is caused by a bacterial infection inside the trunk. There are actually two types of slime flux: 揳lcoholic?and 揳cidic? The acidic flux smells like vinegar.
The infection can be in a wound on the trunk surface or it can be deeper inside the trunk. In either case, bacteria ferment the tree's sap; it seeps out and down to the ground. Sweet-eating insects #wasps, bees, yellow jackets# would obviously be attracted to the damaged area.
There is no treatment for the condition. The best thing to do is to wash off the trunk to discourage bugs. Mix a pint of chlorine bleach in a gallon of water to make a final rinse. The flow of sap is periodic; it may disappear and not reoccur or you may see it every year.
Slime flux is a bacterial disease. The infected wood is frequently discolored or appears water soaked #wet wood#. Gas #carbon dioxide# is produced by fermentation by bacteria. The gas produces pressure in the wood. This pressure forces sap from the trunk through cracks in branch crotch unions, pruning wounds, lawn mower wounds, other injuries and occasionally unwounded bark. This oozing of sap is termed fluxing. The flux is colorless to tan at first but darkens up exposure to the air. As fluxing continues, large areas of the bark become soaked. Many different microorganisms grow in the flux producing a foul or alcoholic smell. Various types of insects are attracted to the slime flux. If the fluxing continues for months, leaves on affected branches may be stunted and chlorotic. Grass may be killed where the flux runs down the trunk onto the grass.
Large mature landscape oaks have had problems with slime flux on the trunk or large exposed flare roots just above the soil line with no apparent wounds or injuries. Sap may continue to ooze for several weeks or months, but usually it eventually stops with no treatment and no apparent damage to the tree. This slime flux may be triggered by heat, drought and other stress.
There is no curative or preventive measures for slime flux except to maintain trees in a general good state of vigor and minimize wounds and injuries. More damage can be done to the tree in attempting to cure slime flux than the flux will do alone.
If there is loose or dead bark in the slime flux area, remove all of the loose bark and allow the area to dry. The best thing to do is to wash off the trunk to discourage bugs. Mix a pint of chlorine bleach in a gallon of water to make a final rinse. The flow of sap is periodic; it may disappear and not reoccur or you may see it every year.
Do not apply a wound dressing.
I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of diameter scattered around the tree and watered in good. This will help improve the overall health of the tree.
