Too much of a good thing

They look so innocent, those sweet pale-blue blossoms that are one of the year's last flowers. Ditto the little plants that sprouted at the foot of the boxwoods, just looking for a little sun. Of course I had to let them blossom and move a few of the plants to a better neighborhood, right?

Not necessarily. Looks can be deceiving. Despite all its good qualities, which are many, this aster (which has been variously identified as large-leaved, heart-leaved, and Short's) has turned into the bully on the block. I will start with the good news.

• This late-blooming aster is an absolute pollinator magnet.
• It can bloom (sporadically) as late as the first week of December in southern Ohio, providing food for any bumblebees that venture out late in the year. 
• It blooms in both sun and shade.
• It tolerates drought and poor soil--basically, it asks for nothing.
• It's pretty and makes a decent cut flower.

The perfect plant, right? Not always, it turns out. 

My garden happens to have good soil, the result of millennia of flooding and leaf mold and decades of tending by a passionate and talented gardener whose work I inherited. (Don't hate me.) This aster is a plant that behaves VERY BADLY in good conditions.

The first year after being introduced to the garden, it played well with its aster cousins in the wildflower bed, making this lovely October display. I dug up some extras for a potted pollinator patch on the back patio and put others in the local plant sale.

The second year, I gave away dozens of asters to friends who wanted to improve their pollinator habitat and dozens more to the plant sale.

The thinning was not enough. At the beginning of their fourth season as more-or-less cultivated plants, these lovely asters are attempting to replicate Ohio native General Sherman's march to the sea.  For the last year, I have been pulling baby asters out of sidewalk cracks, flowerpots, the brick walkway to the back patio, the pollinator bed, and the entire north-facing lawn strip around the corner from the pollinator bed. Asters have invaded the hosta and hydrangea bed and surrounded the lilac, encroached on an ostrich fern planting, and filled an entire corner where they are attempting to choke out the violets and left room for barely a thread of creeping charlie. (Okay, maybe this last is not a bad thing.)  Today I filled a bag that once held forty pounds of potting soil with the corpses of baby asters--and no doubt left some roots lurking in the soil, where they will laugh and send out more runners and create even larger aster patches. 

The moral of the story: no plant is a good plant for all situations. Now that I know what it is, I see this aster growing in fields and meadows and getting along just fine with the other plants there. No monoculture seems imminent. In rich soil, though, it becomes a bully, and if I donate any to a plant sale (whenever we can hold such things again), I will send along a warning label. 

• Give this plant a lot of room. Wild meadows and woodland edges are its natural habitat.
• Do NOT plant it in rich soil. This is a plant that needs to be kept on a diet.
• Do NOT include it in a formal setting, unless you can keep after it all the time.
• Consider confining it in a large container, where it will overwinter with no problem. You will still have to dump the container and dispose of excess asters every couple of years.

It is indeed possible to have too much of a good thing.