Inflorescence
Common Name: lobelia
Type: Herbaceous perennial
Family: Campanulaceae
Zone: 5 to 9
Height: 2.00 to 4.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: July to September
Bloom Description: Purple
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Low
Suggested Use: Annual, Naturalize, Rain Garden
Flower: Showy
Attracts: Hummingbirds, Butterflies
Tolerate: Deer, Wet Soil
Culture
Best grown in rich, evenly moist to wet, well-drained soils in full sun to part shade. Best performance with consistent moisture, but also does well under normal garden conditions. Tolerates full sun in northern climates, but appreciates part afternoon shade in hot summer climates of the lower Midwest and South. Root mulch should be applied in cold winter climates to protect the root system and to prevent root heaving. Mulch will also help retain soil moisture during the growing season. Propagate through seed, division or tip cuttings in spring. Hardy in Zones 5-9.
Noteworthy Characteristics
Lobelia × gerardii is a vigorous hybrid lobelia resulting from a cross between L. cardinalis and L. siphilitica. Mature clumps will reach up to 5' tall with a 2' spread. The growth habit and flower shape are most similar to L. cardinalis. The foliage is dark green, elliptic to ovate in shape, and will reach 4-6" long. Violet to bright purple flowers bloom in summer on sturdy, upright, spike-like racemes. Attractive to hummingbirds, butterflies, and other insect pollinators.
Genus name honors Matthias de l'Obel (1538-1616), French physician and botanist, who with Pierre Pena wrote Stirpium Adversaria Nova (1570) which detailed a new plant classification system based upon leaves.
The hybrid name gerardii honors Professor Rene Gerard (1835-1935), director of the botanical gardens at Parc de la Tete d'or in Lyon, France from 1887-1928. The breeding work to produce this hybrid was undertaken at the garden during his tenure.
'Vedrariensis' features bright purple blooms from mid-summer to early fall. Mature clumps will reach up to 4' tall with a 3' spread.
Problems
No serious insect or disease problems. Snails and slugs may damage the foliage. May be short-lived in the garden. Can be grown as an annual or allowed to self-seed. This hybrid does not typically require staking. Deer tend to avoid this plant.
Uses
Effective in moist areas of woodland/shade gardens, wet meadows or along streams or ponds. Water gardens. Rain garden. Also adds late summer bloom and height to borders as long as soils are kept uniformly moist. Generally not long-lived in the garden, but will self-seed. Can be used as an annual or in a container planting.