That looks to be a very open, even sunny, location. Also maybe somewhat dry? If so, that is pretty opposite of what wintergreen would like - mostly shade and with a moist, acidic and relatively organic soil. Dislikes heat and dry.

Thanks for the response gardengal. The reason why I'm concerned is because I have two other teaberry plants adjacent to it that show no symptoms. Plant is about four feet away from a wood fence on the east side of my property.

Any possible herbicide drift from nearby neighbors?

Yup. Looks like environmental damage to me. Never spray when there is the least bit of air movement!

And it could have come from the local highway group or electric company, as they spray often, and without regard to drift. I have damaged plants in the mountain, and although I have a "no spray" sign at MY property, the adjoining lands do not. Consequently, when they spray, some chemcial drifts down to mine. Sad.

Could also be that your friendly neighborhood dog relieved himself on that one plant. This could lead to such damage, and is worth considering, given that nearby plants of same type were unaffected.

+oM

Thanks for the replies. Is it possible that it'll bounce back. Thinking about it now, I do have an issue with dogs urinating on this side of the property.