I have it and carolinensis self-seeding all over both front and back yards. I don't mind.

I did see these recently but passed as I thought they were ’iffy’ for our zone.

Not iffy at all -- hardy to zone 4.

Where did you see them for sale? Van Atta's in Lansing shows in stock, I'll be travelling through that area soon so may stop in there to see if they still have any.

I wish I could remember. I was all over this year….

I like Ruellia humulis and have been growing it for several years. It is very weedy and has spread everywhere. It's very tenacious. It always is a nice accent to any other plant growing near it. It loves colonizing in between the rocks that edge my beds.

A beautiful combination of Ruellia humulis,(Hairy Wild Petunia, Euphorbia corollata,(Flowering Spurge), and Dalea purpurea,(Purple Prairie Clover), for dry soil.

Mine haven't self-seeded...yet. When I use the term "weedy", I use it more in terms of plant form/habit -- it looks messy. Not really to describe self-sowing tendencies, although I suppose that may be the way it should be used. :0p By my definition, I don't consider Ruellia weedy.

I grew this last year and, probably a bit early, put it in the garden and promptly forgot about it (being teeny still). No sign whatsoever this year (and seem to have misplaced all remaining seeds) Gah.

yes, the long-winded user-name is me, camps, aka rosaprimula, aka suzy...in a new sock puppet account in an increasingly desperate attempt to just manage to post a freaking photo. Have painfully managed to sync the new (ish) laptop to (crap and ancient) phone...with camera. Remains to be seen if I can manage pics. Exhausted by tech right now...off to bed. Wish me luck when I resume tomorrow.

"No sign whatsoever this year (and seem to have misplaced all remaining seeds) "

Oh no! I did have one I put out in the meadow to fend for itself, it was a small specimen and I've never seen hide nor hair of it since.

Ruellia humilis is not native here in Virginia except for a few counties, none of which are near mine. Ruella caroliniensis is so I may look for it. Apparently it can get to a height of 3'. I like your little bunch of it, but not sure I need another 3' clump of anything. Sigh.

I have been 'tending' (ie. ignoring, but not actively killing) this unknown plant all summer, with no idea what I was looking at. Amazingly, it flowered and ta da...it is the only surviving ruellia humilis from last years sowing. It is in the smallest pot (7cm) and has been left to it's own devices, but survived. Now wondering if I should repot in a better substrate and a bigger pot (as it is highly likely to cark, now I am 'looking after' it.

Ruellia humulis is a pretty weed that loves gravelly soil, but will grow in any type soil, and it's very happy growing in pavement. It loves growing in the stones I use as borders.

I want to get another plant with more purplish blooms.

In pavement planning another invasion

In rocks. The long thread-like rhyzomes will regenerate into new plants if they break off when digging up the plants. Plants show up everywhere, but I don't consider them thuggish, I just remove some of them to make room for new different plants. I think there are about 6 named varieties, and a lot more study needs to be done, that will most likely change some taxonomy, and perhaps make some varieties new species. My plants are decumbent, but I've seen some that grow upright.

I have ruellia simplex, Mexican Petunia. It's tall, about 4 or 5', makes a clump, and spreads too much. It's very tough, comes back after 4 degree freezes.

It's going to start blooming pretty soon. (Sept.)

@erasmus_gw, is Mexican Petunia invasive in your area? Anyone in Virginia growing Mexican Petunia could you please comment on it?

Yes, it spreads a bit much within its area but doesn't seem to reseed outside of the bed where I planted it. I have tried to get rid of it with no luck. It's pretty enough.

Note: I'm in zone 7a, NC.

@erasmus_gw, thanks! Your Mexican petunia is very pretty. I planted one many years ago and surprisingly it did not grow. Maybe too much shade. The other day I passed a property and saw it, and thought I want to grow it again. If it is just spreading I can deal with it, so long it does not reseed.