Annual Lobelia Plant: How To Grow Lobelia

lobelia
Image by Daryl Mitchell

By Nikki Phipps
(Author of The Bulb-o-licious Garden)

The lobelia plant (Lobelia spp.) is an attractive annual herb with many varieties. Some of these even include biennial species. Lobelia is an easy-to-grow, carefree plant that enjoys cool weather. This summertime bloomer will continue to produce flowers on up through the first frost. Growing lobelia is an asset to the garden.

Types & Uses of Lobelia Plants

While there are numerous varieties of lobelia plants, only a few are commonly seen in the home garden—L. inflata (Indian tobacco), L. cardinalis (Cardinal flower), and L. siphilitica. Interesting enough, the name of Indian tobacco derived from the fact that Native Americans once smoked lobelia plant to treat asthma. Also known as pukeweed, doctors once prescribed the plant to induce vomiting.

Although most varieties are compact, growing only 3-5 inches tall, others will grow up to 3 feet. Colors are also variable, with white, pink, red, and blue species available. However, violet-blue is probably one of the most commonly seen. These plants make great additions in borders, along creeks or ponds, as ground covers, or in containers—especially hanging baskets.

Growing Lobelia Plant

Annual lobelia will grow nearly anywhere. Lobelia seeds can be sown directly in the garden or indoors for later transplanting. These plants typically require an area with full sun but will tolerate partial shade. They also prefer moist, rich soil. Start indoors about 10-12 weeks prior to the last frost in your region. Spread the tiny seeds just on top of the soil and water thoroughly. Place them in a warm, well-lit area.

The seedlings should pop up within a week or two, at which time you can begin thinning them out. After all danger of frost is gone and the plants are at least 2-3 inches tall, transplant them to the garden—spacing about 4-6 inches apart.

Care of Lobelia Plants

Once established, the lobelia plant requires little maintenance. During hot, dry periods, care of lobelia requires that the plant should receive frequent watering, however, especially those in containers. A general-purpose liquid fertilizer can be given once a month or every 4-6 weeks, if desired.

Lobelia should delight your garden with beautiful blooms about mid-summer, continuing on up to the first frost. Although not necessary, you can deadhead lobelia plants to maintain a neat appearance.

This article was last updated on

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