Cardinal Flower plant photo (Lobelia cardinalis)
Photo: k2018lena · CC0 1.0
perennial
Updated May 2026·Eastern and Central North America

Cardinal Flower

Lobelia cardinalis

Cardinal flower is one of the only native plants in North America with bright pure red color — and it's pollinated almost exclusively by ruby-throated hummingbirds, whose long bills can reach the deep nectar tube that bees cannot.

USDA Zones
3-9
Sun
part sun
Water
high
Mature Size
2-4 ft tall, 12-18 in wide
Growth Rate
moderate
Family
Campanulaceae
Care guide

How to care for cardinal flower

Loves wet feet — perfect for boggy spots, pond edges, or low-lying garden corners that other plants dislike. Short-lived (3-4 years) but self-seeds reliably. Mulch lightly in fall but DON'T pile mulch on the basal rosette.

Garden uses & design ideas

Best garden use

Place it in repeatable drifts through borders so the color and texture carry the eye instead of appearing as a one-off plant.

Pair it with

Joe Pye weed, Iris (water-loving), Astilbe make easy companion choices because they share similar light, water, or visual texture needs.

Layout tip

Match it with part sun exposure, keep it in the same moist-bed zone as other thirsty plants, and check USDA zones 3-9 before planting. Use the garden planner to test spacing around its mature size: 2-4 ft tall, 12-18 in wide.

Gardener note — Double-check local invasive, edible, and toxicity guidance with your county extension office before planting around pets, children, or natural areas.

Companion plants

Cardinal Flower grows well alongside these — similar light, water, and texture needs.

Joe Pye weedIris (water-loving)Astilbe

Common pests & problems

essentially pest-free; deer-resistant

Where it grows best

Native to Eastern and Central North America; thrives in USDA hardiness zones 3-9.

Frequently asked about cardinal flower

What USDA zones does Cardinal Flower grow in?+

Cardinal Flower is hardy in USDA zones 3-9. Outside these zones, it can usually be grown indoors or as a seasonal annual.

How much sun does Cardinal Flower need?+

Cardinal Flower prefers part sun. Place it where it gets that light most of the day for best growth and flowering.

How often should I water Cardinal Flower?+

Cardinal Flower has high water needs. Water frequently — this plant prefers reliably moist soil. Loves wet feet — perfect for boggy spots, pond edges, or low-lying garden corners that other plants dislike. Short-lived (3-4 years) but self-seeds reliably. Mulch lightly in fall but DON'T pile mulch on the basal rosette.

How big does Cardinal Flower get?+

Cardinal Flower reaches a mature size of 2-4 ft tall, 12-18 in wide. Growth rate is moderate, so plan spacing accordingly when planting.

What plants grow well with Cardinal Flower?+

Cardinal Flower pairs well with Joe Pye weed, Iris (water-loving), Astilbe. These companions share similar care requirements and don't compete aggressively for resources.

What pests affect Cardinal Flower?+

Common Cardinal Flower problems include essentially pest-free; deer-resistant. Catching early signs in routine inspection prevents most damage.

When does Cardinal Flower bloom?+

Cardinal Flower blooms in mid to late summer in intense scarlet red. Deadheading spent flowers (where applicable) often encourages a longer bloom window.

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