Great Blue Lobelia

Lobelia siphilitica

$16.00

1 Gallon | Hardiness Zones 4-8

Lobelia siphilitica, known as Big Blue Lobelia, is a perennial Lobelia that produces tall spikes of blue flowers. Each flower is about one inch long and appears in late summer.

This plant grows well in moist soil and prefers partial shade. It suits woodland edges, shaded beds, and areas near water features. It also attracts pollinators during its bloom period.

To maintain healthy growth, divide and replant Lobelia siphilitica every few years. Native to the eastern U.S., it supports native garden plans and adds vertical structure to shade gardens.

Pickup available at Aiken Nursery

Usually ready in 2-4 days

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Grown for Success
Propagated at Woodlanders

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Shipping
Expertly packed & shipped in 2-4 biz days

Plant Specs
  • Zones: 4 - 8
  • Sun: Full Sun and Part Shade
  • Soil: Moist, Well-drained, and Rich
  • Height at Maturity: 2 - 3 Feet
  • Spread at Maturity: 4 - 8 Inches
  • Growth Rate: Moderate

Deciduous

Flower/Foliage

Flower Description:

Lobelia siphilitica produces striking, tubular flowers in shades of vivid blue to lavender, often with a subtle two-lipped structure. The blooms appear densely packed along upright flower spikes, each reaching up to 3 feet (90 cm) tall. Flowering occurs from late summer into early fall, providing a burst of color when many other plants are past their prime. The nectar-rich flowers are highly attractive to hummingbirds, butterflies, and bees, making them a favorite in pollinator gardens.

Fruit Description:

After flowering, Lobelia siphilitica forms small, inconspicuous seed capsules. These capsules contain numerous tiny, brown seeds that can readily self-sow in moist conditions. While the fruits are not ornamental, they contribute to the plant’s ability to naturalize in suitable environments, making it a great option for meadow or wildflower settings.

Foliage Description:

The foliage consists of lance-shaped, medium-green leaves with a slightly serrated edge. The leaves grow alternately along the stem, measuring 3–6 inches (7–15 cm) long. They form a dense, basal rosette from which the flowering stalks emerge. The foliage provides a lush, verdant backdrop for the vibrant flower spikes and remains attractive throughout the growing season, adding texture and fullness to garden beds and borders.

Care Info

Read full care instruction manual here.

Lobelia siphilitica, commonly known as Great Blue Lobelia or Blue Cardinal Flower, is a herbaceous perennial native to eastern and central North America. It is cherished for its vibrant blue flowers and its ability to attract pollinators such as hummingbirds and butterflies.

Planting and Location:

  • Sunlight: Prefers full sun to partial shade. In warmer climates, partial shade during the hottest part of the day can help prevent stress.
  • Soil: Thrives in moist, rich, well-drained soils. It tolerates a range of soil types, including loamy and clay soils, as long as adequate moisture is maintained.
  • Spacing: Space plants about 12 inches apart to allow for proper air circulation and growth.

Watering:

  • Moisture Needs: Requires consistently moist soil. Regular watering is essential, especially during dry periods, to keep the top 6 inches of soil moist. Mulching can help retain soil moisture.

Fertilization:

  • Generally does not require additional fertilization if planted in rich soil. In poorer soils, incorporating compost or a balanced, slow-release fertilizer in early spring can promote healthy growth.

Pruning:

  • Deadheading: Removing spent flowers can encourage continued blooming and prevent unwanted self-seeding. However, allowing some seed heads to mature can facilitate natural reseeding if desired.
  • Cutting Back: After the first frost, stems can be cut back to the ground to tidy the garden and prepare for new growth in spring.

Pests and Diseases:

  • Generally resistant to deer and rabbits. However, slugs and snails may feed on the foliage. Maintaining good garden hygiene and using organic slug control methods can help manage these pests.

Additional Considerations:

  • Wildlife Attraction: The nectar-rich flowers attract hummingbirds, butterflies, and bees, making it a valuable addition to pollinator gardens.
  • Landscape Use: Ideal for rain gardens, woodland gardens, and along streams or ponds due to its moisture-loving nature. It adds late-season color, typically blooming from late summer into fall.

Here’s a closer look at how we produce our plants:

From rooting to shipping, our top priority is ensuring you receive healthy, thriving plants for your garden’s success.

The majority of our plants are carefully cultivated from rooted cuttings, while we also utilize propagation methods such as seed, air layering, and grafting, thoughtfully chosen to suit each plant’s unique needs.

Our plants are cultivated using sustainable practices, including organic soil blends and eco-friendly pest management, ensuring they thrive while minimizing environmental impact.

We are proud to contribute to local biodiversity through ongoing donations to the Aiken Arboretum and support for local wildlife conservation efforts, helping to preserve and enhance our community’s natural ecosystems.

Grown in Aiken, South Carolina

At Woodlanders, we are committed to quality.

All our plant material is carefully propagated, grown, and nurtured at our humble nursery in Aiken, South Carolina.

Learn more about Woodlanders here.

Plant Success Tip #1

Unpack Promptly

Carefully unpack your plant as soon as it arrives. Check the roots and soil to ensure they are still moist. If the roots feel dry, lightly mist or water them before proceeding with planting or temporary storage.

Plant Success Tip #2

Acclimate Your Plant

Allow your plant to adjust to its new environment by placing it in a sheltered spot for a day or two before planting, especially if it has traveled a long distance. Avoid exposing it to extreme temperatures right away.

Plant Success Tip #3

Follow Planting and Care Instructions

Plant your new arrival as soon as possible, following the specific care guidelines provided. If planting outdoors isn’t immediately possible, temporarily pot it in well-draining soil to maintain health until conditions are suitable.

Frequently Asked Questions

What to expect upon delivery

All our plants are sold in 1-gallon sizes, though the height of each plant can vary depending on its growth rate and seasonality, typically ranging from 1/2 to 2.5 feet.

Each plant is carefully packaged with its roots enclosed in a secure plastic bag containing moist soil, forming a compact root ball. To ensure safe transport, the box is padded with recycled newspaper, providing both stability and eco-friendly protection from weather during shipping.

What is your return policy?

Review our full return policy information on our SHIPPING AND RETURNS POLICY page.

What payment methods can I use?

We offer 35 different payment methods including major providers like Mastercard, Visa, PayPal, American Express and Diners as well as many different local payment methods including Klarna, iDEAL, AliPay, Sofort, giropay, and many more.

Can I make changes to my order after it’s been placed?

At Woodlanders, we strive to fulfill orders as quickly as possible. Therefore, we can only accommodate changes to your order within the first 24 hours after it has been placed. These changes include adding or removing products and modifying the delivery address. If you need to make any changes or if there has been a mistake with your order information, please reach out to us promptly via our CONTACT page with your order number for the quickest resolution.

Your satisfaction is our priority, and we appreciate your understanding and cooperation.