Not at all, Guest. It's very well behaved. If you're unhappy that any of its seeds might germinate, then remove the seedheads before the seeds are ripe. I leave them in the soil, as they're so decorative, and not a single seedling has appeared.

I wish mine were invasive. what a bonus !!

We are just getting a few seedlings these days, but not as many as I would like.

Oh, I wish, but as the others say, it's very well behaved, not one of the invasive ones at all.

We have grown them from seed, but rather than letting them drop naturally we took the seed off as soon as the capsules opened and sowed as per normal for Alliums. They do germinate well like that, but 4 years to flowering is getting a bit long for me these days.

Ha ha, know what you mean Owdboggy!