This year I keep seeing plants that appear to be weeds of some description, but the butterflys and bees seem to love them! Is it a bad idea to collect seeds from these and pot them up? (some of them seem really pretty too!)
If the butterflys and bees love them they can't be that bad, weed or otherwise and we need to be encouraging bees whenever we can but you might want to make sure its not something too invasive that'll just just take over, even in pots. Got a picture of said plant you can post?
If you like them thn its not a bad idea. We should all grow the things we like and not be confined by notions of what are weeds and what are not.
Just make sure to ID the plant first and do some research as to how hard it is to control as you don't want to end up with a garden infested with it. I quite like purple toadflax and in my more naive days I happily shook the seed heads all around my garden. Boy, was that a mistake and I've been pulling it up ever since.