Lobelia siphilitica, or Great Blue Lobelia, is a clump forming perennial with tall spikes of deep blue flowers that bloom in late summer. Great option to add vivid cool color and pollinator appeal to native plantings and gardens alike.
Height & Spread: 24 - 36 in x 12 - 18 in
Bloom Time: Late summer to early fall
Light Requirements: Full sun to part shade
Soil Preference: Moist to wet, rich soils
Watering Needs: High; requires consistently moist conditions
Deer Resistance: Moderate
Native Status
Native to eastern and central North America. Commonly found in wet prairies, ditches, and along streambanks where its vibrant blue blooms support native wildlife.
Wildlife & Insects
Butterflies
- Attracts butterflies like Monarchs and Painted Ladies which seek nectar from the tubular flowers.
Bees
- Draws in bumblebees and sweat bees that can access the deep flower tubes for pollen and nectar.
Hummingbirds
- Ruby Throated Hummingbirds are frequent visitors, attracted by the plant’s color and shape during peak bloom.
Spacing & Landscape Use
Spacing Recommendations
- Space 12 - 18 in apart to allow for upright growth and good airflow in moist plantings.
Landscape Placement
- Excellent for rain gardens, wet borders, native meadow edges, and along ponds or streams.
Companion Plants
- Chelone lyonii (Pink Turtlehead) - Combines well with similar moisture preferences and complementary bloom color and shape.
- Aster novae-angliae (New England Aster) - Offers late season color and supports pollinators during similar bloom windows.
- Panicum virgatum (Switchgrass) - Adds vertical texture and seasonal interest while thriving in similar conditions.
- Veronicastrum virginicum (Culver’s Root) - Tall spires add architectural form and attract diverse pollinators to moist borders.
- Rudbeckia fulgida (Black Eyed Susan) - Bright yellow flowers create contrast and thrive in moist native gardens.