Re: what to do with cottonwood seeds?
I've never had to deal with one of those messy things, though there are a few in the neighborhood that send their fluff my way. We've never had any problems with sprouts or anything with the light dusting of dander that we get. I would imagine that you can either rake or vacuum (leaf blower attachment ) up the dander and be done with it. Being a natural substance you could probably compost it, though I'd be concerned that the seed would not be completely destroyed due to inadequate compost heap temperatures and conditions. I'd be more inclined to send it to municipal green waste pick up or the trash can.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!