Overview

Cardinal Flower (Lobelia cardinalis) is a moisture loving native perennial with dazzling red flower spikes from midsummer into early fall. It thrives in sun to part shade with rich, consistently moist soils, stands upright without staking, and brings hummingbirds in close for a dramatic late season show along streams, swales, and rain gardens.

Why You’ll Love It

• Low-maintenance: reliable in sunny, moist spots with modest care

• Hummingbird magnet: tubular scarlet blooms offer prime nectar

• Bold color: vertical spikes light up shade edges and wet borders

Ideal Site & Soil

• Sun first: full sun to part sun for the strongest bloom and posture

• Moisture matters: prefers medium to wet soils and tolerates brief flooding

• Soil texture: loam to clay loam with added organic matter for steady moisture

Planting Steps

• From pots or divisions: keep the crown at soil line, water to settle, and space 12 to 18 inches for airflow

• From seed: surface sow in fall or spring after a brief chill since light aids germination, keep evenly moist

• Placement: use on rain garden shelves, along pond edges, or low spots that stay moist

Care Routine

• Watering: maintain consistent moisture the first season, then water during dry spells

• Feeding: average soil is ideal, avoid high nitrogen that can soften growth

• Mulch: apply a thin, airy layer to hold moisture and keep mulch off crowns

• Grooming: deadhead for tidiness or leave some stalks for reseeding

• Divide: every 3 to 4 years if centers thin, replant vigorous outer fans

Design & Companions

• Rain garden mix: pair with Blue Vervain (Verbena hastata), Great Blue Lobelia (Lobelia siphilitica), and Turtlehead (Chelone glabra)

• Moist meadow partners: Swamp Milkweed (Asclepias incarnata), Joe Pye Weed (Eutrochium maculatum), and New England Aster (Symphyotrichum novae-angliae)

• Sedge and grass matrix: weave with Bristly Sedge (Carex comosa), Brown Fox Sedge (Carex vulpinoidea), and Switchgrass (Panicum virgatum)

Common Mistakes

• Too dry: stress and short bloom, site where moisture is reliable

• Deep shade: lanky stems and sparse flowers, move to brighter exposure

• Heavy mulch against crowns: invites rot, keep collars clear

Quick Troubleshooting

• Flopping spikes: increase sun and reduce nitrogen

• Yellowing leaves in midsummer: drought stress or compaction, irrigate and improve soil aeration

• Poor return after winter: crown heaved or buried, reset at soil line and add thin mulch

Where It Fits Best

Rain gardens, pond and stream edges, low swales, and moist border pockets where vivid color, hummingbird action, and low upkeep are priorities.