Native Habitat:
Wet meadows, streambanks, springs, seeps, marsh edges, and moist woodland openings throughout western North America. In the Pacific Northwest, it is especially associated with moist to wet sites along streams and in mountain and lowland wetlands. It can be grown in Willamette Valley gardens where summer moisture is available.
 
Bloom Time:
June – September
 
Growth Habit & Mature Size:
Perennial herb, generally 1–3 feet tall, sometimes taller under favorable conditions. Plants form upright to somewhat spreading stems with opposite, oval to lance-shaped leaves. Large, showy scarlet-red tubular flowers are produced along the upper stems, with two-lipped flowers adapted to hummingbird pollination.
 
Light & Soil Requirements:
Full sun to partial shade; prefers consistently moist to wet, fertile soils. It tolerates wet soils and performs particularly well along ponds, streams, seeps, rain gardens, and irrigated native borders. Avoid allowing the root zone to become completely dry during summer.
 
Willamette Valley Native Companion Plants:
Deschampsia cespitosa
Spiraea douglasii
Glyceria elata
Symphyotrichum subspicatum
Camassia leichtlinii
Tellima grandiflora
 
Urban Garden Function:
A spectacular plant for rain gardens, pond margins, streamside plantings, wet meadows, and hummingbird gardens. Its brilliant red flowers create a strong focal point in summer while its upright form fits naturally into layered wetland plantings. It is particularly useful for bringing pollinator habitat into gardens that retain moisture through the summer.
 
Wildlife Supported:
Scarlet Monkeyflower is especially important to hummingbirds, which are among its primary pollinators and are strongly attracted to its bright red, tubular flowers. Bumblebees and other large bees may also visit, particularly when they can access pollen through the flower opening. Butterflies and syrphid flies may occasionally forage on the flowers. The foliage supports herbivorous insects, including aphids, leafhoppers, caterpillars, and other larvae, which provide prey for spiders, predatory insects, and insect-eating birds.
 
Historical Use:
Erythranthe cardinalis and related monkeyflowers have been used traditionally by Indigenous peoples in parts of western North America for medicinal purposes, although uses vary considerably among cultures and species. The plant should not be assumed to be medicinally interchangeable with other Erythranthe species.
 
Seed Germination:
The tiny seeds should be surface sown because they require light for good germination. Scatter seeds over a moist, fine-textured seed-starting medium and press them gently into the surface rather than covering them. Cold-moist stratification for approximately 30–60 days can improve germination, particularly with stored seed. After stratification, maintain temperatures around 55–65°F (13–18°C) and keep the medium consistently moist. Germination may occur within several weeks but can be irregular. Once seedlings have developed several true leaves, transplant carefully and keep them consistently moist. For outdoor planting, choose a location where the soil remains moist through the summer.