QuestionQUESTION: I live in northeast Tennessee. I recently planted a pin oak in the spring. It is around 20 feet tall. In the past couple weeks the leaves have turned yellow and now green/brown spots. The trunk has begun to turn black about 3 feet up the tree and has sap bulging out in places. There are flies, hornets, and large Japanese beetles (we call them June bugs) on the trunk. Is it a disease or are bugs inside? Can the tree be saved?
ANSWER: This is called slime flux or wetwood. The foul-smelling and unsightly seepage of sap from the trunk of shade trees is commonly called slime flux or wet wood. It occurs in apple, birch, elm, hemlock, maple, mulberry, oak, poplar and willow.
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.
In your case the stress of the planting caused the flux.
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.
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QUESTION: The leaves are beginning to fall off. Will it still live?
Answertry fertilizing it with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. If it has been dry there water with 1 inch of water per week --place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop.
No one can predict if a tree will die or when. But from your description I would not expect the tree to die from this situation.
