Lobelia siphilitica

Great Blue Lobelia

• Full sun to light shade
• Average to high moisture settings
• 24" to 36" tall, 12" to 18" wide
• Summer to late Summer Blooms
• Garden, wet meadow and shoreline settings.

One of the Lobelia species that grow in my garden, this one is tall, perennial and a showy blue or, in the case of the genetic mix that the seeds I grew came from, white. I believe that the white is a naturally occurring variation.
These are growing in a spot in the garden that receives a bit less sun than they would really like, but they are getting by. The ones in the dappled shade woods do seem to be a bit happier and more robust. These come in to bloom a couple of weeks earlier than their red relatives, although their bloom seasons do overlap.
These seem most content in sun for most of the day and soil that is quite moist at least part of the time. Near downspouts or in a damp corner of the yard would be my top two garden recommendations. Damp meadows would be ideal for natural settings.
Heights vary between 18” and 36”, with a spread of around 8” to 12” and their flowers appear in mid August and continue through mid September, which can make seed maturity a close thing in seasons with an early frost.
As an aside, I’ve heard people talk about smoking lobelia for medicinal purposes. I’ll stay out of the discussion on whether that is safe, but I will note that, rather than this Blue Lobelia, that practice is actually related to Lobelia inflata, which goes by the ‘due for an update’ common name of Indian Tobacco. Inflata is an annual species, with much smaller, pale blue flowers and the puffy seed pods that are the origin of their botanical name.