Considering that B. davidii and its hybrids and B. lindleyana are on the noxious weed list in NC and other areas, and that the common blue and white ones spring up with regularity at a friend's house, I doubt it's too difficult. If you REALLY want to, (which I don't recommend unless it's one of the rarer species, which don't seem to be as much of a problem [yet]), then I would suggest that you try winter sowing, and maybe try both covering the seeds and leaving them exposed, in separate pots, to see which works best.

According to this site, Buddliea seeds don't require chilling but do require light.

I have and it grew very tall in the first season - It even flowered. This is and caryopteris were very easy to grow.

Carrie

PS I never covered the seeds and wintersowed them.

Carrie

Noxious weed? Somehow I can't put B/Bush in the same league as honeysuckle and stiltgrass. Now, if they want to add Chinese/Siberian Elm, that would make sense to me.

Love BB and only had a few volunteers over the years. EZ transplants when you've had second thoughts about pitching them after ripping them out of the soil.

Thanks to all for the info.
I hadn't considered that it might be on the noxious plants list so I checked via the usda.gov site and did not find it listed there for South Carolina. (I'm in the upstate area.)
I've posted the link, in case anyone else wants to see what IS on the list.

Here is a link that might be useful: SC Noxious List

Those lists are great but I can't understand why they don't have a link to an actual photo so people can tell right away what to pull out and dispose of.

i've had it reseed naturally into my driveway. i'd heard it was considered a bit of a weed in some areas because of seediness. i try to keep mine deadheaded.

The only place I've had seedlings is the bonfire pit. I don't think it has any particular requirements that are satisfied by ash, but there's not much competition in there.

There is a recent post on the Winter Sowing forum concerning growing butterfly bushes from seed. I don't think any of the posters live in the Carolinas though. I've only ever bought live plants or had them already growing on the property at purchase.

Been growing various butterfly bushes for almost 15 years, 3 different states and NEVER had ONE reseed for me. I've never seen one out in the wild either.

I have 3 BB, 1 white and 2 dark purple. this spring I noticed about half a dozen seedlings in the general area of these. I dug them up and replanted them elsewhere. 1 has started blooming and it is a light purple. I don't know about the others yet. I don't know how I got a different color than the 3 originals, but the wife likes it.

Can someone please tell me how to collect seeds?
Mine don't reproduce, I wish that I had seedlings.
Are they the dried flower heads? Can you try for seedlings right away, or should I wait til next spring?

I have not grown them from seed, but I do know that it takes a long time after the flower is dead for the seeds to show up. I have propagated from cuttings which is real easy. All I do is cut right under a leaf, take off the leaves, just leaving a few at the top, stick it in soil in a pot and keep watered for a while. Originally I keep it in the shade, but when I can pull on the stalk and it doesn't easily move, then I start adding sun to its routine. I plant them once they have been in full sun for a while.

I've had great success wintersowing butterfly bush seeds.
I haven't had any reseeding from my plants but a number of my plants have been seed-grown.

Good luck!

Here is a link that might be useful: How to collect Butterfly Bush seeds

I have a huge butterfly bush but I don't try to harvest the seeds. All the winter birds feast off the bush and dropped seeds all by themselves all winter long.

Seeds from this bush need to be stratified. Four weeks in the freezer with some dead flower heads will promote germination. The seeds mist not be covered with soil only pressed down as they need lots of light to germinate. The easier way to propogate BB is to make a cutting and put it in some water until roots appear, and then plant it in a starter pot. I also live in Upstate SC.