Great Blue Lobelia

Lobelia siphilitica - Starter Plug 

IMPORTANT PICKUP INFORMATION 

THIS ITEM IS ONLY AVAILABLE FOR PICKUP ON APRIL 25, 2026, FROM 10 AM TO 12 PM AT GREENVALE VINEYARDS, PORTSMOUTH, RHODE ISLAND.

There is no delivery option for your seedling pre-order. You must pick up your plant yourself on the seedling sale date. Any seedlings not picked up will be considered a donation to ERICD's educational farm program.

What You'll Receive:

One (1) Great Blue Lobelia starter plug - a young, healthy plant with an established root system, ready to add cool blue spires to your late summer garden. 

Add cool blue spires to your late summer garden with Great Blue Lobelia! This moisture-loving New England native brings true blue color when most gardens are dominated by yellows and oranges. Perfect for rain gardens, pond edges, and consistently moist borders, its tall flower spikes create architectural interest while supporting native pollinators. More tolerant of garden conditions than Cardinal Flower, this species adapts to average moisture with supplemental watering. 

Outstanding Features:

True Blue Color: Provides rare true blue flowers in late summer and fall when this color is scarce in the garden.

Native Pollinator Plant: Attracts bumblebees, butterflies, and hummingbirds; the tubular flowers are especially designed for long-tongued pollinators.

Extended Bloom: Flowers continuously from July through October, providing nectar during critical fall migration periods.

Adaptable: While preferring wet conditions, tolerates average garden moisture better than Cardinal Flower with regular watering.

Plant Specifications:

Light: Full sun to partial shade (4-8 hours)

Soil: Rich, humus-rich soil; tolerates clay

Moisture: Wet to medium-moist; requires consistent moisture

Height: 2-3 feet tall, 1-1.5 feet spread

Bloom Time: July to October (mid-summer to fall)

Hardiness: Zones 4-9 (excellent for New England) 

Growing Tips:

Plant starter plugs 12-18 inches apart in spring or fall. Great Blue Lobelia performs best with consistent moisture but doesn't require standing water—mulch to retain moisture and protect roots. In average garden soil, provide supplemental water during dry spells. Apply light winter mulch in zones 5-6. Divide every 2-3 years in spring to maintain vigor. Self-sows moderately. Ideal for rain gardens, bog gardens, pond margins, or consistently moist perennial borders throughout Rhode Island and Massachusetts.