This plant came with young forsythia that I bought from a store and is now outgrowing. Can anyone identify it?
Thank you for your response! Flower buds are still white. Maybe this is a white flower variety or turns pinkish later.
It may be a Eupatorium, but not E. purpureum which has whorled leaves. Perhaps Eupatorium serotinum.
Another to consider is White Snakeroot, Ageratina altissima. (formerly named Eupatorium rugosum)
Here is a link that might be useful: White Snakeroot
Thank you all for the responses! I'll see how it looks like when it fully blooms.