Annual Lobelia – Grow and Care for Lobelia erinus

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.lobelia erinus


  • 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
  • It is a member of the Campanulaceae family of plants

Physical Description

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.

Growing Conditions

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.


Purchase Seed

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Garden Uses

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.

Lobelia Erinus on one of my relatives outdoor steps. This flower will be shaded in the afternoon, and should bloom until Autumn.


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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annual lobelia Lobelia erinus

Be sure to check out these other articles, I think you would find useful, as well:

How to Remove Sod by Hand – Our Easy Method

How to Make DIY Tick Tubes

Reasons to NOT Build Raised Bed Gardens

Our Simple Method to Compost

Our Easy Method to Remove Grass By Hand

Native Plant Profiles

Invasive Plants



Joe Foster

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 10 years. I hope to share some of my knowledge with you! You may have seen some of my videos I create on our YouTube channel, GrowitBuildit (more than 10 million views!). You can find my channel here: 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!

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