Thanks Rick! I think that's what I needed to know more than anything. Now I can really cut them back!
I've got lots of other seed to add to the mix, so these won't be all alone. I just didn't have any seed left for this particular plant, so I needed to collect the seeds. I always let everything reseed outside of the garden area, which would be anything outside of the large fenced in yard. Growing conditions are kind of brutal here, so finding something that grows well takes some time to figure out. These do great with no additional water from me, so I'm hope the deer and bunnies don't kill them all off!
