April 12th, 2008 The Gall Of It!
Making our annual spring yard inspection, we noticed a swelling on a branch on one of our variegated willow standards. (Photo above)
The swollen area is the start of a gall disease, caused by insects, bacteria, or fungi.
Galls ususally only look unsightly, but cause no serious damage to the tree.
To prevent the gall from spreading, remove the afflicted branch. Do this by making an undercut first (Photo at left). The cut should be started several inches from the trunk of the tree. Cut into the branch about one inch.
Next cut the top of the branch, right above the undercut.
The reason you make an undercut first, is to prevent tearing of the bark which can cause more damage.
After you have removed the branch, cut the stub back to the trunk. Make a straight cut, never angled. Straight cuts generally expose less inner bark and tissues of the tree. That in turn, gives insects, and diseases less area to invade.
Cross section of the inside of the gall. The blackened portions are insect eggs waiting to hatch.
The tree should now be safe from further infestations of gall.
