Lobelia is a common herbaceous annual garden flower that is compact and well behaved. It is very often sold in garden centers and nurseries. It is a good choice for a flower along the edge of a garden or a pot, as it will bloom until mid-summer or fall depending.
Also known as Edging Lobelia, Lobelia Erinus is native to South Africa – it is not native to North America. But since it is so commonly found, and we are adding a general Lobelia category soon I figured we should write a post describing it, its uses/biology, etc. I have several family members who purchase some each year to have in pots in partially shaded locations.
Is native to South Africa
Although it is an alien plant, it is not invasive, meaning it won’t start to take over a yard or grow in other areas on its own
It is hardy to zone 10, so for almost all of the Continental US this flower will die in the winter
This plant is used in some medicines for respiratory ailments
This is a compact plant generally growing 6-9″ tall (15-22 cm) and a spread of 6-12″ (15-30 cm). It prefers partial shade but can survive in full sun if given supplemental water. It will produce many blooms the full season, and the bloom themselves are interesting as are all Lobelia blooms.
Stalk / Stem
Multiple small stalks will emanate from a central root. These are generally erect. However, there are so many hybrids available that you can often find varieties that hand down / trail.
The leaves are generally lance-shaped, being about 2-3″ long by 1/2″ wide. I’ve normally seen them in a rosette. But, depending on the variety you purchase this may vary.
There will be multiple flowers that are grouped at the top of the stalk. These groupings are called racemes. Each flower is tubular in shape, and will have several petals below and two above. I think it resembles an open mouth.
How to care for Lobelia Erinus
Provide a full sun or partial shade location for the best performance of this flower. It likes fertile but well drained soil. If outdoors in full sun, provide much supplemental water based on the soil moisture levels. These plants can dry out.
Spent blooms should be removed via deadheading. This will promote another round of blooming. This can also keep the plant looking neat and tidy. Other than that, this plant probably won’t require any maintenance to stay looking nice and healthy.
How to Establish
You can grow Lobelia Erinus from seed by direct sowing seed indoors about two to three months before the last frost. You should get germination within a couple of weeks. Then, just move the seedlings to a location indoors where they can get sunlight, and nurse them until there is no chance of frost.
Once you have no chance of frost, you can begin to move the seedlings outdoors during the daytime. This process is called ‘hardening off’, and will acclimate the seedlings to colder weather. After a week or so of doing this, you can plant into the garden, hanging baskets, or pots.
Lobelia Erinus is a good choice for the edge of a well manicured flower bed. They also are commonly grown in planters of pots to place on a front porch or a back deck.
Bees and butterflies will visit the flowers.
Pests and diseases
These plants are generally considered deer resistant. Disease are also not a problem.
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Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over six years. I hope to share some of my knowledge with you!
Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!