Hi Stacey, Thank you for taking the time to report weeds! A good source to learn what weeds we are mostly worried about in the gorge is the "Worst Weeds of the Gorge" booklet which can be found at: https://columbiagorgecwma.files.wordpress.com/2017/09/cg-edrr-booklet-17.pdf
This publication was created by the Columbia Gorge Cooperative Weed Management Area.
While Lemon balm is definitely very weedy, it is not on the list b/c it is not quite as invasive as some of the others. It is also still grown agriculturally.
Again, thank you for keeping an eye out for us and reporting when you find something! That is very helpful to land managers.

Emily Stevenson
Feb. 7, 2019, 6:37 a.m.