Lobelia is a flowering herbaceous perennial, native to southern Africa, and a member of the bellflower family. In the wild, it is typically found in forests or natural areas, in moist woods and fields, and the edge of streams. It is winter hardy within a narrow set of USDA sub-tropical zones and is often grown as an annual in cooler climates north of zone 10. It seems to do much better with cool springs than with hot or humid summers. The plant is relatively small (4 to 9 inches), but produces heavy blooms of colorful flowers in late spring well into the summer. Cultivars can have an upright or trailing form and offer many different flower colors, including blue, violet, purple, red and pink, often with yellow or white eyes. Trailing forms are excellent for hanging baskets while the upright form lends itself to edging and flower beds. Lobelia does best in organically rich, moist, well-drained soils in full sun to part shade with regular applications of fertilizer every two weeks in the growing season. It should be consistently watered and does not tolerate drought. It can be difficult to grow from seed, but an annual planting of purchased plants can be more successful. After each flowering, and especially when the foliage and flowers begin to fail in summer, you can cut the plant back for new blossoms. Diseases, Insect Pests, and Other Plant Problems: Under wet conditions, watch for damping-off, stem rot, or root rot. More information on Lobelia .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; High Organic Matter; Loam (Silt); Sand
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Mature size
Height: 0 ft. 6 in. - 0 ft. 9 in. | Width: 0 ft. 6 in. - 1 ft. 0 in.
Maintenance
Medium
Canopy layer
5 - Groundcover (<1 ft)
Form & Appearance
Habit / form
Erect; Spreading
Leaf color
Brown/Copper; Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Linear; Obovate
Leaf margin
Serrate
Leaf size
< 1 inch long
Hairs present
No
Leaf detail
Narrow, linear, serrate stem leaves (to ½” long) may be flushed with bronze. Leaves higher on the stems are slender and sometimes untoothed.
Flower color
Blue; Pink; Purple/Lavender; White
Flower value
Showy
Flower form
Raceme
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
Flowers are white, scarlet, or blue, 5-parted, tubular and irregular-shaped with 2 lips and yellow to white throat. Typically blooms from April to June. Flowers are about 1/2 inch with fan-shaped lower lips.
Ingesting large quantities of any part of the plant can cause nausea, vomiting, diarrhea, salivation, exhaustion and weakness, dilation of pupils, convulsions, and coma.
Toxic principle
Alkaloids lobelamine, lobeline, and others, plus a volatile oil.
Contact dermatitis
No
Toxicity summary
Medium severity poison; parts: Flowers; Fruits; Leaves; Roots; Sap/Juice; Seeds