Asteraceae
Scarlet Dahlia (Dahlia coccinea) Care Guide
Dahlia coccinea
Grow in full sun with rich, well-draining soil kept evenly moist during the growing season. Deadhead spent blooms regularly, feed with a low-nitrogen fertilizer, and lift tubers before frost in cold climates to store them over winter.
Every 3 days
Direct sun
10° - 29°C
40% - 60%
Categories
What is Scarlet Dahlia?
Scarlet Dahlia (Dahlia coccinea) is a medium-care plant from the Asteraceae family. Dahlia coccinea, the scarlet dahlia, is a tuberous perennial native to the mountainous regions of Mexico and Central America. Prized for its vivid single blooms in shades of red, orange, and yellow with a golden center, it is considered one of the wild ancestors of modern garden dahlia hybrids and i...
Scarlet Dahlia grows up to 1.5m, spread of 60cm, watering every 3 days, 10°C – 29°C, 40–60% humidity. It is not suitable for indoor environments and not safe for pets.
Without precautions, ingestion can cause irritation in pets. Keep out of reach of cats and dogs.
How to Care for Scarlet Dahlia?
TLDR: Scarlet Dahlia needs Direct sun, watering every 3 days, and temperatures between 10-29°C with 40-60% humidity.
How Often Should You Water Scarlet Dahlia?
Water deeply two to three times a week during active growth, keeping the soil consistently moist but never soggy; soggy soil quickly leads to tuber rot.
How Much Light Does Scarlet Dahlia Need?
Provide at least 6-8 hours of direct sunlight daily; too much shade results in leggy growth and fewer flowers.
What Is the Best Soil for Scarlet Dahlia?
Plant in rich, loose, well-draining soil amended with compost; heavy clay should be lightened with grit or organic matter to prevent waterlogging around the tubers.
What Pot Should You Use for Scarlet Dahlia?
Use a wide, deep terracotta or plastic container (at least 30-40 cm deep) with generous drainage holes to accommodate the spreading tuber clump and prevent waterlogging.
Care Schedule
Fertilize
Every 21 days
Repot
Every 365 days
What Is Scarlet Dahlia and Where Does It Come From?
Dahlia coccinea, the scarlet dahlia, is a tuberous perennial native to the mountainous regions of Mexico and Central America. Prized for its vivid single blooms in shades of red, orange, and yellow with a golden center, it is considered one of the wild ancestors of modern garden dahlia hybrids and is celebrated as a symbol of Mexican botanical heritage.
How to Propagate Scarlet Dahlia?
Tuber Division
Always sterilize cutting tools between divisions to prevent spreading rot, and discard any soft or diseased tubers.
- 1 Lift the tuber clump after the first frost blackens the foliage
- 2 Let tubers dry and cure for a few days in a cool, airy spot
- 3 Divide the clump with a clean knife, ensuring each division has at least one eye near the crown
- 4 Store divisions in dry peat or vermiculite over winter in a cool, frost-free place
- 5 Replant divisions outdoors after the last spring frost, eye facing up, 10-15 cm deep
Materials needed:
Seed Propagation
Seed-grown plants will bloom the first year but may not match the parent plant's exact color.
- 1 Sow seeds indoors 6-8 weeks before the last frost in seed-starting mix
- 2 Keep soil moist and at 18-21C until germination
- 3 Transplant seedlings outdoors once frost danger has passed
- 4 Expect flower color and form variation since dahlias cross-pollinate readily
Materials needed:
How Big Does Scarlet Dahlia Grow?
TLDR: Scarlet Dahlia can reach up to 1.5m tall with Medium growth rate.
Max height
1.5m
Spread
60cm
Growth rate
Medium
Foliage
Deciduous
Warning: Toxic Plant
This plant can be toxic if ingested. Keep out of reach of:
Plant Uses
Ornamental
Great for decoration
Edible
Can be consumed
Medicinal
Medicinal properties
Medicinal Uses
- Tubers used in traditional Mesoamerican medicine for digestive ailments
- Sap historically applied to minor skin irritations
Culinary Uses
- Tubers historically roasted or boiled as a starchy food source, similar to potatoes
- Petals occasionally used as an edible garnish
Is your plant showing symptoms?
Click on the symptom to discover possible causes:
What Diseases Commonly Affect Scarlet Dahlia?
TLDR: Scarlet Dahlia is susceptible to 6 known diseases. Monitor regularly for early detection.
Powdery Mildew
Powdery mildew is a common fungal disease caused by various fungi species including Erysiphe, Podosphaera, Oïdium, and Leveillula. It affects over 10,000 plant species worldwide. The disease thrives in warm, dry climates with high humidity and appears as a distinctive white powdery coating on plant surfaces.
Root Rot
Root rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.
Aphids
Aphids are small, soft-bodied, pear-shaped insects (1/16 to 1/8 inch long) that feed by sucking nutrient-rich sap from plants. They reproduce rapidly and can quickly weaken plants, causing distorted growth and transmitting plant viruses. Aphids come in various colors including green, black, red, yellow, brown, and gray. They secrete honeydew, a sticky substance that attracts ants and encourages sooty mold growth.
Slugs and Snails
Slugs and snails are mollusks that feed on plant tissue, causing irregular holes in leaves and damage to young seedlings. They are most active at night and in moist conditions, leaving characteristic silvery slime trails. These pests can quickly devastate gardens, especially during wet seasons.
Meaning & Symbolism
Represents resilience, creativity, and inner strength; historically linked by the Aztecs to the sun and to warriors, and later adopted as a Victorian symbol of lasting commitment.
Fun Facts
Dahlia coccinea is one of the wild ancestor species behind thousands of modern dahlia cultivars.
The Aztecs called the dahlia "acocoxochitl" and used its hollow stems as water pipes.
The dahlia is the national flower of Mexico, chosen in 1963.
Each dahlia bloom is technically a cluster of many tiny flowers packed into a single flower head.
Frequently asked questions
Is Dahlia coccinea toxic to cats and dogs?
How often should I water Dahlia coccinea?
Can Dahlia coccinea survive winter outdoors?
Are Dahlia coccinea tubers edible?
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| Muriel's Bamboo | Medium | Partial shade | 3d | ✓ |
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