Scarlet Monkey Flower (Mimulus cardinalis)

Scarlet Monkey Flower botanical diagram

About Scarlet Monkey Flower

Scarlet Monkey Flower (Mimulus cardinalis) is grown for garden performance matched to its site needs. Expect full sun or partial sun, typically 0.3–0.91 m tall, high water once established.

Sun Full, Partial
Water High
Height 1–3 ft (30–90 cm)
Spread 1–3 ft (30–90 cm)
Bloom Jun–Aug [1]
Origin North America [2]
Season Spring, Summer, Fall
Hardiness Zones 7–10

Can Scarlet Monkey Flower take your winter? Type your ZIP below and compare it with Zones 7–10.

2023 USDA ZIP listings (PRISM / USDA-ARS). Find Your USDA Hardiness Zone · Official USDA map.

Is Scarlet Monkey Flower Right for Your Garden?

Best for

  • Mixed borders and general garden use
  • Reliably moist soil or pondside positions
  • Open, sunny positions with good air movement
  • Wildlife-friendly gardens — known to attract butterflies

Not recommended if

  • Free-draining or sandy soils prone to drying out
  • Dense shade or north-facing walls

Trade-off to know

Scarlet Monkey Flower thrives in moisture but will not tolerate stagnant waterlogging. The distinction between 'moist' and 'wet' matters — good drainage is still required.

Growing Conditions for Scarlet Monkey Flower

Site checklist

  • Sun: full sun or partial sun
  • Soil drainage: Poorly Drained
  • Water: High
  • Hardiness zones: 7, 8, 9, 10

Adjustments

  • Wrong light level is the most common cause of weak performance
  • Fix drainage before treating leaf symptoms

Shared growing steps for this plant’s group: How to Grow Monkey Flower. Notes below stay specific to this plant.

How to Care for Scarlet Monkey Flower

Establishment

  1. Plant Scarlet Monkey Flower in a site matching its sun and drainage needs
  2. Water regularly until roots settle, then match watering to the plant’s need

Ongoing care

  • Mulch to buffer moisture swings
  • Remove dead or damaged growth in season
  • Avoid constant wet foliage where disease pressure is high

Diagnosing Problems with Scarlet Monkey Flower

SymptomLikely causeConfirming signAction
Leaves yellowing, soft, or dropping in wet conditions Waterlogging or root rot Soil soggy; roots brown and soft when uncovered Improve drainage before replanting Scarlet Monkey Flower. Do not water until the top 5 cm of soil is dry.

Leaves yellowing, soft, or dropping in wet conditions

Likely cause
Waterlogging or root rot
Confirming sign
Soil soggy; roots brown and soft when uncovered
Action
Improve drainage before replanting Scarlet Monkey Flower. Do not water until the top 5 cm of soil is dry.

Scarlet Monkey Flower FAQ

  1. Is Scarlet Monkey Flower easy to grow?

    Scarlet Monkey Flower needs reliable moisture and is not suitable for dry or neglected gardens. The most common mistakes are poor drainage and incorrect sun placement.

  2. How big does Scarlet Monkey Flower get?

    Scarlet Monkey Flower typically reaches 0.3–0.91 m. Final size depends on soil quality and available root space. Allow adequate spacing at planting — most plants reach their full spread within 5–10 years.

  3. How much sun does Scarlet Monkey Flower need?

    Scarlet Monkey Flower grows best in full sun or partial sun. Planting in the wrong light level is the single most common cause of poor performance. Check the aspect of your site before choosing a position.

  4. Does Scarlet Monkey Flower attract wildlife?

    Scarlet Monkey Flower is known to attract butterflies, hummingbirds. For maximum benefit, avoid deadheading all flowers — seed heads and spent blooms are often as valuable to wildlife as the flowers themselves.

What Scarlet Monkey Flower Symbolises

  • enduring
  • constant
  • steadfast
  • reliable

References

  1. [1] GBIF occurrence phenology — Bloom months inferred from StillImage observation seasonality (temperate Northern Hemisphere filter). Not an official cultivar calendar. - https://www.gbif.org/species/6070720
  2. [2] GBIF species distributions — Native range summarised from GBIF distribution records; locality noise filtered to country and macro-region terms. - https://www.gbif.org/species/6070720

Taxonomic identifiers

  • https://www.gbif.org/species/6070720 (GBIF 6070720)
  • https://www.wikidata.org/wiki/Q3314650 (Wikidata Q3314650)
  • https://powo.science.kew.org/taxon/tro-29200081 (POWO tro-29200081)
  • https://www.ipni.org/n/805898-1 (IPNI 805898-1)

Plant details on Bosquelle are curated from published references and garden practice. Height, bloom time, hardiness, and look still shift with climate, soil, and care — use this profile as a reliable starting point, then check what local growers see in your area.