Silphium Species, Cup Plant, Cup-Plant

I grew cup plant when I lived in southern Michigan (zone 5a). It got very tall, up to 6 ft. or more, in not terribly fertile soil. I did ...Read Moreusually have to contain the clump or it would slant and spread open when it bloomed.

The pros are that it’s a very striking, low-care (except for the staking) plant, it’s a native plant, and birds love it. The big con is that it’s a hugely prolific self-seeder, and I didn’t find the baby plants very easy to remove.

But if you have a big prairie-type space, go for it!