Bladder Gall Mites on Maple: Prevention Timing

Why Sprays Fail Now

Once galls form, the mites are enclosed and protected. The only window to treat is mid-April, before bud swell, when adults move to new growth.

Perspective

• Galls are unsightly but rarely reduce tree health.
• Heavy infestations may cause early leaf drop, but sufficient foliage remains.
• Chemical control is seldom warranted.

If you must spray, use a labeled miticide (e.g., carbaryl) at the proper spring timing.