Question
We have a Sweet Gum Tree in our front yard that is well over 30 years old. I have just noticed that it now has a white, bubbling liquid seeping from the trunk base; it has never done this before. Over the years the roots have become more and more exposed- it sits right by the sidewalk. Could this be a disease of some kind?

Thanks

Answer
This sounds like either slime flux or alcoholic 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.

Alcoholic or white flux also called frothy flux, is not related to wet wood. It occurs where microorganisms ferment sap in cracks and other wounds in the bark and cambial region. Alcoholic flux is acidic and nearly colorless, and sometimes appears as a white froth. It often emits a pleasant fermentative odor, and persists only a short time in summer. The associated microorganisms apparently produce gas and alcohol. Alcoholic flux is reportedly common on stressed trees, notably on Liquidambar stryaciflua (sweet gum), Quercus (oak), and Ulmus (elm) in the Midwest and Salix (willow) in the Southwest.

Alcoholic flux is stress related. In this case, heat stress mostly likely set the stage for this problem. To help avoid this problem, good cultural practices should be maintained. Proper watering during the growing season as well as during the winter months is critical. Since this tree is in a lawn, care must be taken to avoid over watering and other damage such as caused by lawn mowers and string trimmers.



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.

Control of wetwood and slime flux in forest tree stands is impractical. Infected ornamental trees may be helped by pruning declining branches, and fertilizing to promote tree vigor and wound closure. Fertilize with 10-10-10 fertilizer at the rate of 1 lb of fertilizer per inch of trunk diameter scattered round the tree and watered in good. Apply just before a rain storm and you will not need to water. Fertilize now and again in the fall.