Question
i have a small sumach in my small city garden.it is approx 10-
15 years old.it has several patches of weeping sticky substance
that is cream in colour and bleeds when poked rather like an abcess.the garden is rather too full with too many trees and
shrubs for its size and it has been very wet all this summer
and last year as well.any idea what is wrong and how to fix it?

Answer
Hi.Sounds a lot like wetwood.
Wetwood is a bacterial disease.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. 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 is called "slime flux" and is caused by a bacterial infection inside the trunk.
There are actually two types of slime flux: 揳lcoholic攁nd 揳cidic? The acidic flux smells like vinegar. The flux is colorless to tan at first but
darkens up with 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.The flow of sap is periodic; it may disappear and not reoccur or you may see it
every year.

Large mature landscape trees 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 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. Try 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 wetwood than the flux will do alone.   City trees struggle a lot more than urban trees. Hope this helps.Bill