Lobelia siphilitica

Also Known As

Blue Cardinal Flower
Great Blue Lobelia

Plant type

perennial

size

H: 24"
W: 16"

planting zones

5a-9b

More Options

Lobelia siphilitica plant details

Lobelia siphilitica is a broadleaf deciduous perennial with green foliage. In fall and summer blue flowers emerge. Attracts butterflies and hummingbirds making it an excellent addition to pollinator gardens. Grows well with sun - mostly shade and even moisture water. Does well in average and well-drained soil.

CHARACTERISTICS OF Lobelia siphilitica

Plant type: perennial
Plant family: campanulaceae
Foliage: deciduous green
Mature size: 16 IN wide, 24 IN tall
Flowers: blue blooms in fall and summer
Uses: border plant, cottage garden, cutting garden, easy-to-grow, floriferous, long-blooming, toxic

GROWING CONDITIONS for Lobelia siphilitica

USDA Zones: 5a - 9b
Sun exposure: sun - mostly shade
Watering frequency: even moisture
Resistant to: deer and rabbit
Soil needs: average and well-drained

Nursery contributed plant descriptions

From the streams, sloughs and swamps of the eastern Unites States comes this lovely bloomer, perfect for damp situations, 2-3' stalks with tubular flowers of a deep blue or (some-times white); wonderful for moist or wet soils and just perfect for rain gardens . S-PSh/M-W

By: Forestfarm

Lobelia siphilitica was once used to treat syphilis now it is used to grace gardens. The beautiful blue spikes of great blue lobelia do remarkably well without staking in sun to part shade. The blue is stunning against its pale green leaves and is useful to create a delphinium-like effect in shadier parts of the garden. Enjoys a moist soil but will do well in average sites as well. Native to much of eastern North America.

By: Phoenix Perennials and Specialty Plants Ltd.

Native to eastern areas, it was named by Linnaeus, who had heard of its use by Native Americans to cure venereal disease. While false, the name stuck. Used medicinally for colds and stomach troubles by Native people and colonists alike. The flowers cover the stout stems with bloom for over a month in late summer. Rich, moist soils. Poisonous.

By: Select Seeds

Once used to treat syphilis now it is used to grace gardens. The beautiful blue spikes of great blue lobelia do remarkably well without staking in sun to part shade. The blue is stunning against its pale green leaves and is useful to create a delphinium-like effect in shadier parts of the garden. Enjoys a moist soil but will do well in average sites as well.

By: Premier Landscaping & Yard Care

Great Blue Lobelia (Lobelia siphilitica) is covered in deep blue flowers in late summer and early fall. It can form colonies of flowered spikes in medium to wet soils, especially with a little shade. Longer lived than the Cardinal Flower, it also attracts hummingbirds. Planted together, the two Lobelias make a stunning combination. Excellent for damp clay soil. Hardy to Zones 3 - 9.