Garden Q&A
The bubbling pine and the gall of forsythia
This looks like one of the many manifestations of slime flux. Slime flux is caused by a surface bacteria that enters and feeds in a small bark crack or tiny wound. Gasses produced by the bacteria build up and push out sap. Seeping sap most often appears as a constantly wet area on the trunk. Other times the sap looks whitish or beige. It can ferment and have an alcoholic odor, attracting insects.
In your photo, the gases are blowing bubbles. With enough pressure, the tree can even “whistle” — quite startling if you happen to be walking by. No treatment is recommended for slime flux. It’s fairly benign.
As always, prevent unnecessary injuries to trees, e.g. mulch to keep mowers at bay. (Mulch should never be in contact with a trunk and only 3 inches deep max.)
Stem galls on forsythia were diagnosed previously as Phomopsis, a fungal disease. It is known now to be a bacterial disease called
Since flowering occurs at tips, yes, this is a problem. All you can do is prune back each branch to healthy wood.
To prevent spreading the disease, do this during dry periods and disinfect your pruning shears between cuts. Alcohol wipes may be easiest to use. Dispose of diseased branches in the trash; do not compost. Though pruning away all galls may mean virtually eliminating the plant, forsythia are so tough they should grow back eventually.
If you do not want to wait, consider replanting with an early-blooming native shrub.