Hi Jean, yes sweet Autumn does get very large but it could also be controled with some pruning or dug up and divided after several years.I don't think its invasive like a vitalba that spreads all over your yard from its seeds.

Jean,
I've had SAC for years and I would not call it invasive. It's a big plant so make sure you put it where you have room but it does not send out runners. I've had a few seedlings, but only 2 or 3 a year. I dig them up and take them to our plant swap. Don't be afraid of this vine, you'll love it!

I think the term "invasive" gets thrown about too much without a good understanding of what it means. I know which forum and thread you were referring to and few of the plants discussed are truly invasive - that is, able to spread at will, usually by seed, and colonize natural areas to the detriment of native plant populations. Aggressive is another feature altogether and is typically used to describe garden plants that grow rampantly, spread easily or are difficult to eradicate once established in your garden, but do not pose a threat to natural habitats.

I'd describe SAC as an aggressive vine in that it grows rapidly and is big. Allowing insufficient space for it in a small garden could pose problems :-) And while it may generate a few seedlings (mine never has), it certainly cannot be considered invasive in the correct use of that term.

SAC is aggressive. Mint and bee balm are invasive.

In Kansas Zone 6, no one plants Sweet Autumn. It grows and spreads on its own--everywhere! A real pain.

Kate