I spotted this brilliant pink growth on a small oak tree beside our cottage. Any ideas as to what it is?—Sherrie Adam, Wahsoune Island, Ont.
A tiny pink clown wig. A wad of cotton candy. A hair scrunchie from the ’90s. No, that’s an oak gall—specifically, a “woolly” or “mossy” gall, says Douglas Justice with UBC’s department of botany.
These types of galls are caused by wasps, and they’re relatively common—they just don’t always look so neon. “The pink is definitely unusual,” says Justice.
The growth happens in response to the wasp laying eggs inside part of the tree, says Matt Logan, the co-owner of Logan Tree Experts, which operates in the Kawartha region. “This reaction—to surround the intruder in plant material—actually works to the wasp’s benefit,” he says. “It creates a safe home for the eggs to hatch and the larvae to grow.”
Here’s how to tell how old a tree is
Unless the clown wig truly offends your eyeballs, no need to do anything about it. A gall is unsightly, but it’s not likely to harm the tree. “Galls are primarily a drain on the tree’s energy,” says Logan. “So a healthy tree should be fine.” Plus, like solitary bees, solitary wasps, such as gall wasps, rarely sting and are beneficial insects.
Got a question for Cottage Q&A? Send it to answers@cottagelife.com.
This article was originally published in the August 2024 issue of Cottage Life
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