Blue Lobelia, Lobelia silphitica

Looks like Lobelia.

Yes, lobelia siphilitica. I love this but I find it very aggressive in my garden. The soil is very wet (standing water at some times of year), part shade/part sun. The lobelia seeds a lot so I try to cut it back before it goes to seed. I have to have SOME in my garden lol - can't bring myself to get rid of it completely!

:)

Dee

I agree it can be aggressive. I made the mistake of planting 3 about 3 years ago but dug them up at the end of that year because I read that they can be invasive. I am still pulling babies up 3 years later, and I mean a lot of them.

They only spread from seed, and are so easy to pull, that I think agressive and invasive shouldn't be used as descriptions of Lobelia siphilitica. I've never known them to have excessive amounts of seedlings, and I've been growing them for decades. They don't self seed to the extent that Impatiens capensis does, and yet Orange jewlweeds can be easily pulled out also. Agressive, invasive paranoid disorder.

Mine have never been aggressive/invasive...and I wouldnt mind a bit if it did! Love that blue....

The key is to cut them back before they seed out. Not hard to do,

Jay, I almost always agree with stuff you post, but I have to speak up here. I am neither paranoid nor do I have a disorder! :)

In MY garden, which is what I said, lobelia siphilitica is very aggressive. If I don't cut it back in time (which admittedly I don't always get to do, as much to my dismay I can't spend all my time in the garden) it spreads way too much. Perhaps it's the garden - as I said, very wet, standing water at times - and maybe these conditions are more agreeable to spreading than in your garden. And I've been growing it maybe not for decades but for at least 15 years, and there are times when I regret planting it.

This area also has TONS of jewelweed, which I try to keep OUT of the garden but leave it outside the garden along the creek bank, and the lobelia is MUCH more difficult to pull. A much stronger, thicker, denser root system, which pulls up big clods of wet soil with it, and which needs much more effort to pull - I often have to use a claw to assist, whereas jewelweed comes right up. Actually, I often wonder when I pull the lobelia if there's so much soil on the roots that it just reroots where I throw it in the big pile in the woods!

Everyone has different experiences with plants, and I think when someone asks a question, it's good to hear all of them. I know I like to hear different perspectives when I ask a question. And yes I agree completely that the key is to cut them back before they go to seed, which is what I said above, but we can't always get to things in a timely manner, and so I think people should be aware of what happens when they can't.

:)

Dee

Wow, thanks all. Invasive ...not liking that. I wonder if humming birds like them.

I appreciate all the comments on this thread. I've been considering lobelia siphlitica for a semi-wild garden. The garden already contains ditch lilies, phyostegia virginiana and ostrich ferns. I have a two gallon pot of cherry bells to add this fall. I need aggressive plants that can out compete wine berries, poke, scuppernongs, poison ivy, hackberry seedlings, etc. It will get weedwhacked each spring.

jerseyjohn, it's not invasive. I've found it to be an aggressive reseeder in optimal conditions, but it is not invasive. If you have room, let it reseed and it will likely colonize beautifully. If your garden is smaller you might want to cut it back to cut down on its spread. And yes, I have seen hummingbirds on them!

:)

Dee

How much shade will it take? Thanks.

When plants are gone and I'm still pulling up babies 3 years after they were pulled out I consider it aggressive. Maybe they like the damp area near my pond, who knows but I regret planting them.

I planted 6 of them 8 years ago and after approximately 3 years they had seeded themselves everywhere in my gardens. I have pulled out hundreds of them. (Muskoka, Ontario, Canada, zone 5a). Now I make sure I cut the seed heads off. They are a major ”weed” in my garden, but too pretty to get rid of entirely