Bouncing Bet is one form of soapwort. It resembles phlox, white/pastel pink flower, blooms most of the summer. Pretty, but be warned, there is a reason it is called "bouncing" bet. It will be here & there throughout your garden. Not a bad thing really I think, & I've found it pretty easy to pull up if you get too much of it. Easy to winter sow.

As long as you have it in an area where it won't be ignored you should be OK. It spreads underground runners close to the surface next to the mother plant. Make sure you dead head so it doesn't go to seed. I didn't follow these instructions and have been pulling it out of an area every year. As Heathen1 stated there are much worse invasive plants than Saponaria officinalis.

---To decide what species if in question, I would (and do) use an image search. 100 different pics of hummers visiting the same one should guide you in the right direction.--- Perhaps you are not aware of the practice, but many photographs of hummingbirds feeding at flowers actually have a commercial feeder hidden behind them. Those sneaky photographers! ;^) That way they can have the flash units and camera set up where the hummingbird is pre-conditioned to feed. I always chuckle when I see flowers that naturally grow upright, hanging upside-down in the photographs. This wasn't meant to take your thread off-track, but to highlight that the popular photography flowers may not be hummer favorites.

I'm growing both. The bouncing bet I knew was crazy so I put it where it could do that whole aggressive ground cover thing where I didn't care. I didn't know the blue mist was so it's might end up corraled in a pot (with a saucer under it) in the "tamer than most" bed. I haven't decided yet. All of the plants here have some aggressive tendencies so I might just be able to "weed out" where I don't want it before it clobbers the other plants. The blue mist (gregg's blue mist btw) with it's apple green foliage and fluffy purple flowers that attract so many butterflies is just too pretty to give up.