The flower color is beautiful, a clear violet-purple. This plant lacks the big leafy bracts of L. siphilitica that detract from the flowe...Read Morers (at least in my opinion). Flowering stems stand up without support for me in partial shade.
I cut the main stem back partway when bloom seemed to be ending, and secondary stems extended the bloom season into October.
I wonder whether, if I pin the stem down along the ground early in the season, it will root at the nodes and produce many new plants that way? I know that works for L. cardinalis. I'm sure I won't even lose the bloom, because the nodes send up secondary flowering stems.
Armitage says that plants in commerce may be a cross between L. siphilitica and the tender L. x speciosa 'Queen
Victoria'. That would account for the occasional reddish tinges to the foliage, and hardiness less than either L. cardinalis or L. siphilitica.
Mine didn't survive its first Z6a winter.
Update 5/2016: Tried again last year, it bloomed well last summer and survived a slightly milder winter than usual.
The RHS lists this as L. x speciosa, which means it may have hardiness problems here. It is sterile, which means it can be propagated by division (or layering, or cuttings) but not by seed.
In commerce, this is often listed (incorrectly) as Lobelia x vedrariensis.
Someone ought to try crossing L. siphilitica with L. cardinalis 'Chocolate Truffle', for both purple leaves and increased hardiness.
I whish I could write a positive review on the color alone, but this plant always flops in my garden so it looks more messy than pretty,...Read More sadly... And the individual plants are not very dense, they do not fill up to make a nice drift. The flowering period is long enough though.. Why does it flop like that for me? It is in full sun. Normally, plants flop in too much shade or when the soil is too rich, which is definitely not the case there. Could it be too dry or too poor for this one? I am puzzled...
This is a great substitute for delphinium in hot humid areas. While the delphiniums are dropping dead in my garden, this lobelia looks g...Read Morereat in August-Sept with its tall, dark purple spikes.
To keep this plant from dying over the winter, be sure to pull out the old crowns, and do not mulch the rosettes. They are hardy to at least zone 4, if they heave, just push them back in the ground.
I love this plant. I had it growing in its pot in the pond this year - not entirely in the water, just about half the pot submerged, and ...Read Moreit looked gorgeous. Being in the pond kept slugs/snails off, too. Will see how we get on next year..
The flower color is beautiful, a clear violet-purple. This plant lacks the big leafy bracts of L. siphilitica that detract from the flowe...Read More
I whish I could write a positive review on the color alone, but this plant always flops in my garden so it looks more messy than pretty,...Read More
My plants crossed on their own and my resulting plants are cranberry colored not purple like those pictured above.
This is a great substitute for delphinium in hot humid areas. While the delphiniums are dropping dead in my garden, this lobelia looks g...Read More
I love this plant. I had it growing in its pot in the pond this year - not entirely in the water, just about half the pot submerged, and ...Read More
Lobelia x Gerardii is a hybrid between L. Cardinalis and L. Siphilitica. Vedrariensis has red tinted foliage and purple flowers. pokerboy.
A tall hybrid perennial.
Has lance shaped, mid-deep green leaves sometimes blushed with red. Bears 5 lobed, 2 lipped purpl...Read More