I don,t know what your seed are,but you sound so excited about them.I would like a few of them.How about some pumpkin tree seed.My tree is about six ft.tall With about 75 pumpkins on it .They are about the size of a golf ball.N.C.zone7

I would love to trade for some cup plant seeds

Wow - I couldn't find a picture of the seed- and I do not remember what mine looked like when I tried it years ago- but I did find some information that may be useful, It is in the Aster family, and the seeds ripen in August. The scented flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects. So, all heads have the potential to have seeds- "The fruit is a brown obovate achene with an emarginate apex, appearing in autumn. Sometimes 2-toothed." So- methinks it is very similar to an aster seed- more so than a sunflower seed (although it could be wrapped in the husk like a sunflower) or a zinnia (flat with 2 teeth) or a rudbeckia (rod shaped)- I really wish I had a pic- or a better description- but I hope this little bit will help you- Julie

I bought a tiny twig of a Cup Plant on a garden walk two years ago. Last season it bloomed gorgeously from one stalk. This year I have 4 gorgeous blooming stalks. Next year? I assume it will multiply again. I have it in an area where it will be happy for a few years before I start worrying! That is not to say it isn't "easy" to control - the woman I bought it from simply dug out a twig that was next to the mother plant. I plan on doing this next year if my plant produces more offspring. Like many things, it may also self-seed easily; I controlled this by deadheading and planting the seeds in a contained area. The seedlings are easy enough to identify and pull out if need be! Perhaps it might be a little more aggressive in your slightly-warmer zone. The worst problem I've had is not invasiveness - but staking! Mine only gets a few hours of direct sun, so I'm sure that's why after a heavy rain/wind storm it looks a little tippy. So in answer to your question, I don't think this plant is any more invasive than a lot of butterfly/bird friendly plants out there (I think echinacea and milkweed are worse offenders when it comes to self-seeding!). Hope that helps. :) Sandy