A Plant I Didn't Even Know I Had

Have you ever been given a plant and you were told it was something then it turned out to be something else completely different? That happened to me back at the plant swap this spring. I was given several pots of 'Black and Blue' Salvia that day and didn't look at any of them very closely. I was in a hurry when I planted all the plants I brought home (which must have been more than two dozen) and planted plants as quickly as I could. Then I forgot about them and they began to grow.

Later I noticed that this one plant in particular looked very different from what it was "supposed to be." They were all seedlings when I adopted them and as seedlings looked vaguely similar but as they grew the leaves changed. Then the salvias began blooming while the other plant was still all foliage. A couple weeks later the buds began to form in small clusters of little fuzzy ball shaped buds. Immediately I had a suspicion as to what its identity was but needed it to bloom to be sure. Here's how it appears today:

A hardy ageratum or blue mist flower (Eupatorium coelestinum). This is just now starting to bloom but should last well into the fall. It should return next year (zones 5-9) and could reseed.

It's always nice to have more blue in the garden!