Hardy Planting Zone – Zones 3 to 9
Bloom Season – July to October
Bloom Color – bright blue
Height at Maturity – 2 to 3 feet
Soil Type Preferred – moist to wet soil, clay, loam, or sand
Sun or Shade – partial shade
Great blue lobelia offers a striking blue splash of color for your home garden.
Also called the blue cardinal flower, the great blue lobelia is native to a broad middle to the Eastern United States. Great blue lobelia most commonly grows near water in the wild, mainly preferring ponds, creeks, swamps, meadows, woodlands, and springs. Great blue lobelia is a perennial that grows as a single, unbranched stem with tight clusters of lavender-blue, tube-like flowers. Occasionally, these plants may demonstrate minor branching. Flower color can vary from light blue to nearly purple. The flowers themselves have an upper lip with two petals and a lower lip with three petals. The plant's stiff, leafy stem usually grows 2 to 3 feet tall, though it can sometimes grow even taller. Leaves are lance-like, light green, and toothy. Leaves can grow up to 5" long.
This plant is very easily cultivated in various soils and light conditions, from partial shade to full sun in northern climates. Partial shade is preferred further south. The soil must be kept medium to wet with constant moisture, and the plant responds well to humidity.
Great blue lobelia offers some natural resistance to damage from deer, and great blue lobelia has no significant disease or insect problems.
Great blue lobelia is the perfect plant for attracting friendly hummingbirds and butterflies to your garden. The great blue lobelia is recommended for perennial borders, woodland gardens, or wild gardens. Since it naturally grows near bodies of water, planting great blue lobelia near home streams and ponds can be particularly striking and effective.