@johnbishop Sawtooth sunflower needs full 8 hrs + sun or the stems may lean... I have not seen whether the plants can support birds feeding on them. Here is the cup plant link at the same nursery https://www.prairiemoon.com/silphium-perfoliatum-cup-plant-prairie-moon-nursery.html I love the leaves, and the birds love to feast on the seeds. The left over canes after the plants dry are sturdy enough to use as kindling.
Both of these will plants spread as far as you let them - not for small, neatly manicured garden spaces, but wonderful on a fenceline or edge of wild space. My friend just mows her cup plants if they spring up outside the allotted bed. I aggressively lop off the extras at the ground. And as natives, once established they don't need much minding, extra water, fertilized, seem pest free...
Getting off my garden soapbox now and going out to lounge by the pond...
Sue