Will these galls kill my tree?

No, they are a natural part of the sumac's life cycle and rarely cause lasting damage.

Should I spray my tree with insecticide?

It is usually best to avoid it, as insecticides can harm the pollinators and beneficial predators that keep your garden in balance.

Smooth sumac: pests, causes and fixes

Check these first

Look closely to see if the bumps are hollow galls or hard insect shells.
Check if the leaves are otherwise healthy and green.
See if there is any sticky residue on the leaves.

Likely causes

Sumac gall aphids
Most likely
How to tell: You will see small, irregular, or round growths on the leaves that look like little galls. These are created by aphids as a protective home.
What to do: You generally do not need to do anything as these do not kill the tree. If you dislike the look, simply prune off the affected leaves and dispose of them in the trash.
Scale insects
Possible
How to tell: These look like small, hard bumps on the stems or leaf veins that do not move. They may cause yellowing or stunted growth.
What to do: Scrape them off gently with a soft brush or apply a light horticultural oil during the dormant season. Avoid heavy pesticides as they often kill the beneficial insects that eat aphids.

Pests on other plants

Find out what's wrong with your smooth sumac

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

When to worry

Only worry if the infestation is so heavy that the entire plant is losing leaves or showing significant decline. Most gall aphid cases are purely cosmetic.

Stopping it coming back

Keep your sumac healthy with proper sun and water, as stressed plants are more susceptible to heavy pest pressure.

Smooth sumac: pests? Check yours with a photo

Every plant is a little different. Take a photo of your smooth sumac and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

Get the app · Or check it from a photo now, free

Questions people ask

Will these galls kill my tree?: No, they are a natural part of the sumac's life cycle and rarely cause lasting damage.
Should I spray my tree with insecticide?: It is usually best to avoid it, as insecticides can harm the pollinators and beneficial predators that keep your garden in balance.

Guides to these causes

Scale Insects

What are these bumps on my Smooth sumac leaves?