Question
QUESTION: A few weeks ago, I noticed what at a distance looked like someone spray painted some black vertical lines which ran down the trunk on one of the Maples in our planting strip by the street.  I don't know what kind of Maple except to say it is what the City and developers love in the strips and is everywhere. The tree is about 16-18 years old.  The trunk splits into 3 major branches.  The black is on only one of the three.  There are vertical cracks in the bark where the black seems to like to be. The cracks are about an 1/8th of an inch deep and range from 2" to 18".  In the worst spot, seems it "emits" from bumps from previous small limb pruning 1+ years ago, but not at all of them.  I can see the orangish under the bark in the cracks.  The black appears to run down the trunk following perhaps where water runs off.  Some spots look wet but are not wet. No trees around it are effected.  Live in Seattle, WA. See pictures. jpg's zipped into one zip file.  Change the jpg extension to zip and it will work.  Site wouldn't "set" the zip as an image.... What can/should I do about it?  Thanks very much.  John

ANSWER: The pictures did not come through please try again.

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QUESTION: Trying the zip file with extension editted to be jpg again.  Change name so extension is zip and see what happens.  If this does not work, is there an email I cna send to directly instead of through site?  Not, I looked up above the main spot and did not see aphids, ants, or other appearant source point for a drip above.  Thanks, John

Answer
I would think this is a condition called slim flux.
Slime flux is the name given to the oozing or flowing liquid that is often seen during the heat of the summer on the trunk, large limbs, or basal roots of oak, elm, maple, apple, yellow- poplar, birch, hemlock, and willow. It is usually more common on large, older trees than younger ones.

Slime flux is what you see; however, it is caused by a condition inside the tree called wet wood. Wet wood is caused when bacteria invade a wound or injury caused by anything from construction damage to lawn mowing. This invasion, not the injury, is the good part! The bacterial growth creates pH and micro-element conditions in the wood that are undesirable for the development of wood decay organisms. In other words, wet wood is a defense against decay and not the fungi that might eventually cause a cavity to develop.

As time passes, the fermenting wet wood-causing bacteria produces methane gas which pressurizes the fluid in the wood under the bark that has grown over the injury. When enough pressure is created, the gas causes the wet wood liquid to ooze, flux, or bubble through the bark. Once in the oxygen-rich environment on the surface, this odorless and colorless or tan liquid darkens. It may or may not be colonized by yeast-like fungi. If the yeast-like organisms colonize the ooze, they grow and produce a foul, yeast or alcoholic smell. Then the flies, hornets, wasps, and sap beetles begin visiting and feeding on this brew of foamy, frothy, fluxing, fermenting slime.

Wet wood or slime flux will not in itself kill a tree. The fluxing is an outward sign of some type of previous injury to the tree. Whether the tree lives or dies will depend on the extent of the previous injuries and the amount of stress to which the tree has been subjected. If fluxing continues for a long period of time, the flow of liquid can discolor the bark, kill moss and lichens on the bark, or kill grass at the base of the tree.

Avoiding stressing the tree further and providing care that improves growing conditions are the best things you can do for a tree with slime flux. Depending on how much gas the wet wood is producing and how well the tree closes the wound, the fluxing may or may not be recurring.

If the flow, smell, or insects become objectionable, particularly on a tree near the front door or beside the patio, periodically flush the area with a stream of water or very diluted solution of household bleach and water. This will lessen the smell and discourage the insects from congregating.

Keep in mind, this often smelly flux is actually caused by a condition inside the tree that is protecting the tree from more damaging decay organisms. That's an unusual mixed blessing, isn't it?

When I said the pictures did not come through I meant none were attached to the question.