Outing Those Damned Spots on the Maples | Environment | Seven Days | Vermont's Independent Voice
Pin It

Outing Those Damned Spots on the Maples 

Local Matters

VERMONT -- It's been a lackluster year for Vermont's leaf peepers, and the problem wasn't helped any by a particularly nasty outbreak of "giant tar spot." This new and unsightly leaf blight, which only afflicts Norway maples, began showing up this summer throughout Chittenden County and other sections of Vermont, and has hit Burlington's Hill Section especially hard. But according to City Arborist Warren Spinner, the problem is nothing for residents to get too concerned about, since it usually doesn't threaten the health of an infected tree.

Giant tar spot is caused by a fungus that typically occurs after an unusually wet spring. The fungal spores lie dormant in leaf litter from the year before and spread to the new leaves when they bloom in May and June. By mid-summer, the blight appears on maple leaves and samaras. It resembles large, raised droplets of tar -- hence the name. This particular tar-spot variety, which is new to Vermont, doesn't seem to affect sugar, silver or red maples.

"Is this going to set the tree back or kill the tree? Normally, it does not," Spinner adds. Though giant tar spot can prematurely defoliate a tree, Spinner says that by the time the spots appear, the tree has already completed much of its photosynthesis for the season.

While there's no easy way of getting rid of tar spot, Spinner recommends raking up leaves and getting them off the lawn before next spring. Residents shouldn't worry that adding infected leaves to compost will further the blight, he notes, since the spores are already ubiquitous throughout the county.

Will the black spots mar the landscape next year as well? It all depends on the weather, Spinner says. If next spring is unusually dry, the spots may not appear at all.

Got something to say? Send a letter to the editor and we'll publish your feedback in print!

Pin It

More by Ken Picard

About The Author

Ken Picard

Ken Picard

Ken Picard has been a Seven Days staff writer since 2002. He has won numerous awards for his work, including the Vermont Press Association's 2005 Mavis Doyle award, a general excellence prize for reporters.


Subscribe to this thread:

Add a comment

Seven Days moderates comments in order to ensure a civil environment. Please treat the comments section as you would a town meeting, dinner party or classroom discussion. In other words, keep commenting classy! Read our guidelines...

Note: Comments are limited to 300 words.

Recent Comments

Social Club

Like Seven Days contests and events? Join the club!

See an example of this newsletter...

Keep up with us Seven Days a week!

Sign up for our fun and informative

All content © 2017 Da Capo Publishing, Inc. 255 So. Champlain St. Ste. 5, Burlington, VT 05401
Website powered by Foundation