How to Grow Scarlet Monkey Flower
Erythranthe cardinalis
A California/Oregon native perennial with bright scarlet-red tubular flowers that hummingbirds love. Unlike most California natives, this one needs consistently moist soil — plant along streams or in boggy areas. Partial shade to full sun (needs afternoon shade in hot climates). Flowers spring through fall with adequate moisture. Cut back after flowering to encourage reblooming. Can spread by runners in moist conditions.
Yearly Lifecycle
Care Essentials
Light balanced feed in spring as new growth emerges. Avoid heavy feeding — these plants are adapted to lean, streamside soils and excess fertility encourages leggy growth at the expense of flowers.
Watch For
- Aphids on young shoots and flower buds
- Snails and slugs — especially in the moist conditions this plant requires
- Powdery mildew if soil dries out or airflow is poor
Companions
Cardinal Flower (Lobelia cardinalis), Western Columbine, Ferns, Sedges, Japanese Iris
Track your Scarlet Monkey Flower care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Partial shade to full sun; afternoon shade in hot climates
Grows best with morning sun and afternoon shade in warm regions. In cool coastal climates, tolerates full sun if soil stays moist. Avoid deep shade which reduces flowering.
💧 Watering
Consistently moist soil — not drought-tolerant
Unlike most California natives, Scarlet Monkey Flower demands constant moisture. Water regularly throughout the growing season — soil should never dry out completely. Ideal near streams, ponds, or in bog gardens. Mulch heavily to retain moisture.
🌱 Fertilizing
Light balanced feed in spring; avoid heavy feeding
A single light application of balanced fertiliser in early spring is sufficient. These plants are adapted to lean streamside soils — excess fertility produces leggy growth with fewer flowers.
✂️ Pruning
Cut back spent stems midsummer; remove all growth in late autumn
After the first flowering flush fades in midsummer, cut back spent stems to encourage a second bloom. In late autumn after frost kills the foliage, cut all growth to ground level.
🪨 Soil
Moist, humus-rich; tolerates clay if not waterlogged
Prefers consistently moist, humus-rich soil. Tolerates clay soils better than most perennials as long as they don't become stagnant. Add organic matter generously at planting time. Slightly acidic to neutral pH (5.5-7.0).
Growing Tips
Keep soil consistently moist
This is not a drought-tolerant California native. Scarlet Monkey Flower naturally grows along streams and seeps. If the soil dries out, flowering stops and powdery mildew moves in. Mulch heavily and water during dry spells.
Hummingbird magnet
The tubular scarlet flowers are perfectly adapted for hummingbird pollination. Plant near a window or patio to enjoy watching them visit. Flowers continuously from spring through fall with adequate moisture.
Control spread in ideal conditions
In consistently moist, rich soil, Scarlet Monkey Flower spreads vigorously by runners. This is desirable in naturalistic streamside plantings but may need containment in formal borders. Pull unwanted runners in spring.
Log Scarlet Monkey Flower in your garden — track growth, care, and harvests year after year
Start planning free