Great Blue Lobelia

Great Blue Lobelia For Sale

Great Blue Lobelia plants dazzle with tall spires of vivid blue flowers that light up late summer gardens and attract hummingbirds and pollinators in abundance. Their striking color and elegant form bring a bold, natural beauty to borders, wildflower gardens, or water’s edge plantings. Hardy and easy to grow, they thrive year after year, making them a must-have for any gardener who wants both color and ecological impact.

The Great Blue Lobelia flowers from late summer to mid-autumn, producing a raceme of adorable, blueish, two-lipped flowers. The inflorescence rises tall above its finely toothed, wavy-edged foliage that persists along a rigid stalk. It can reach heights of 2-3 feet and form clumps that eventually spread throughout the growing area.

Their flowers are long-lasting. With their emergence in late summer and early fall, they are not only an important food source for pollinators but also provide a floral display long after spring-flowering perennials have died back, rounding out the season for your garden.

Plant Details – Lobelia siphilitica (Blue Lobelia)

Family: Campanulaceae

Hardiness Zones: 4 to 9

Light Requirement: Full sun to partial shade

Water Needs: High

Height: 2 to 4 ft

Spread: 1 to 1.5 ft

Growth Rate: Moderate

Bloom Time: Mid-summer to early fall

Flower Color: Light to dark blue

Wildlife Value: Attractive to pollinators

The Blue Lobelia is known for its medicinal properties. Native Americans used this plant to treat nosebleeds, coughs, and headaches. It was even used to treat symptoms of syphilis, from which it was given its Latin name of “siphilitica.”

Great Blue Lobelia's Garden Uses & Growing Tips

These perennials are pest—and disease-free, deer-resistant, and easy to grow, requiring little to no maintenance. They prefer moist to wet soils with rich humus. To encourage more flower production, deadhead this plant once the flower spike is finished. 

 Great Blue Lobelia Plants Greatest Assets In a Garden

Late summer – autumn flowering, attractive to pollinators, grows well in wet soil.With its tall flowering stalk and clump-forming growth habit, this perennial will add unique layers of texture and vibrant color to your garden to keep you looking forward to its late summer flowering season. 

This Is How Your Plants Will Look upon Delivery

Bloom Season

Fall

Bloom/Foliage Color

Blue

Height at Maturity

Over 12"

Care

Blue Lobelia thrives in well-drained, consistently moist soil. Regularly water to moisten the soil, especially during hot, dry periods. Fertilize lightly in early spring, and remove spent flowers to encourage continuous blooming—mulch to retain moisture and suppress weeds.

Plant Reproduction

Blue Lobelia spreads by reseeding, dividing clumps, or taking cuttings.

How to Grow and Care for Bare Root Perennials, Tubers, and Bulbs

Bare root perennials, tubers, and bulbs are an easy and economical way to jumpstart your garden with lasting beauty. These dormant plants should be planted in early spring or fall while the soil is cool and workable. Before planting, soak bare roots in water for 1–2 hours to rehydrate them. Choose a location based on the plant’s light needs—most flowering types prefer full sun, while others thrive in partial shade.

For bare root perennials, dig a shallow hole and spread the roots out naturally, ensuring the crown is level with the soil surface. For tubers and bulbs, plant with the pointed side facing up at a depth about two to three times their height. Cover with soil, gently press down, and water thoroughly.

Keep soil consistently moist (not soggy) until new growth appears. Add mulch to retain moisture and suppress weeds, but avoid covering the crown or bulb tops. Once established, these plants require little maintenance—just seasonal watering, occasional dividing, and deadheading or pruning as needed. With proper care, they’ll return and thrive year after year.

We carefully package every plant to retain superior moisture during transit. Once prepared, orders ship the same day through UPS or USPS, with typical delivery in 2–4 days.

Returns are not accepted, but plants are reshipped if extended warranty insurance was purchased at checkout. Otherwise, all plants include a standard 5-day warranty after delivery.