Tree Dahlia
dahlia imperialis
Also known as: ["Columbia Tree Dahlia","Giant Tree Dahlia"]
Overview
A tall, woody-stemmed species of dahlia native to Central and South America, known for its large, showy flowers and rapid growth.
Benefits & Perks
["long-flowering","fast growing","wildlife attractant (bees, butterflies, birds)","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Dahlia |
| Botanical Name: | Dahlia imperialis |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: sheltered garden bed or large container
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"10–30°C"}
- Hardiness: {"zones":"8–11"}
- Misting: every 2–3 days in dry conditions
- Drainage: Well-draining to fast-draining; avoid heavy clay soils.
- Soil Type: Rich, loamy soil with good organic matter; well-draining to prevent waterlogging.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Deadhead flowers weekly during blooming season; light shaping as needed in spring or early summer.
- Pruning Intensity: Light to moderate; avoid heavy pruning unless necessary to control size or rejuvenate old growth.
Care Details
Ideal Sunlight Coverage:
Full sun to partial shade (4–6 hours of direct sunlight daily); tolerates dappled light in hotter climates.
Sunlight Tolerance Tips:
Acclimate gradually to intense sunlight; protect from harsh afternoon sun; adjust placement based on seasonal light intensity.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
partial shade to full sun
Rotate plant for even growth; provide shade during peak summer heat; monitor for sunburn signs.
Watering
every 5–7 days during active growth, reduce in winter
Water thoroughly until runoff, allow soil to dry slightly between waterings, and avoid overhead watering to prevent fungal issues.
Soil
well-draining, rich in organic matter
pH: Slightly acidic to neutral (pH 6.0–7.0).
Ensure soil is not compacted; avoid overwatering; enrich with organic matter annually.
Temperature
Prefers mild temperatures (60–75°F or 15–24°C); thrives in moderate climates with cool nights.
Protect from frost; avoid sudden temperature swings; maintain consistent moderate temperatures.
Fertilizing
every 4–6 weeks during growing season
Apply fertilizer after watering; avoid contact with stems or leaves; flush soil occasionally to prevent salt buildup.
Propagation
Methods
Stem cuttings or division of rhizomes; stem cuttings are more common for home growers.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Maintain humidity.
Best Time: Spring, when new growth begins; rhizome division is best done in early spring before active growth.
Environment
Warm (70–75°F or 21–24°C), high humidity (70–80%), and bright indirect light.
Medium
Well-draining mix of peat, perlite, and sand; can also root in water initially.
Hormone
Recommended to use rooting hormone for faster and more reliable rooting.
Timeline
Roots develop in 3–6 weeks; new growth appears in 2–4 months; full establishment takes 6–8 months.
Tools Needed
Pruning shears, rooting hormone, pots, well-draining medium, humidity dome or plastic bag.
Quick Tips
Use healthy, non-flowering stems; keep soil consistently moist; provide bottom heat if possible.
Pruning & Repotting
Pruning Guide
Method
Pinch back tips for bushier growth; cut spent flowers just above a leaf node; remove yellow or damaged leaves.
Pruning Plan
Remove spent flowers to encourage continuous blooming; prune leggy growth to maintain shape and improve air circulation.
Tools
Clean, sharp pruners or scissors, gloves.
Checklist
Clean tools before use; prune at the right time; make clean cuts; remove debris after pruning.
Repotting Guide
Best Season
Early spring, before new growth starts.
Pot Size
Increase pot size by 2–3 inches in diameter; ensure good drainage holes.
Method
Gently remove plant; trim any dead roots; place in a slightly larger pot with fresh, well-draining soil; water thoroughly.
Suggestions
Repot every 2–3 years or when roots fill the pot; beneficial for rejuvenation and fresh soil.
Checklist
Choose appropriate pot size; prepare fresh soil mix; handle roots carefully; water after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture with a finger; water deeply; ensure drainage; adjust frequency with weather.
How to Apply Water Properly
Water directly at the base of the plant, ensuring moisture reaches the root zone; water early in the morning to minimize evaporation and allow foliage to dry before nightfall.
Watering Schedule Tips
Water deeply once a week during active growth, increasing to twice weekly in hot or dry conditions; reduce watering in winter dormancy.
Soil Improvement
Add compost or well-rotted manure for fertility; mix in perlite or sand for drainage; use mulch to retain moisture.
Temperature Stress Management
Signs of Temperature Issues
Wilting, leaf scorch, stunted growth, or premature flowering in extreme heat; leaf drop or root rot in cold stress.
Cold Stress
Low temperatures slow growth and can cause root damage or dieback, especially in frost conditions.
Solution: Provide frost protection (mulch, row covers); plant in sheltered locations; avoid overwatering in cool weather.
Hot Stress
Excessive heat leads to wilting, leaf burn, and reduced flowering; may go dormant if conditions are too harsh.
Solution: Increase watering frequency; provide afternoon shade; use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Use diluted fertilizer; apply during active growth; avoid winter feeding.
Fertilizing Method
Use balanced liquid fertilizer (10-10-10) every 4–6 weeks during growing season; reduce or stop in winter.
Common Problems & Solutions
Toxicity Warning
Cats
Slightly ToxicCats may suffer mild gastrointestinal issues if they consume the roots or stems of Dahlia imperialis. The plant is not highly toxic to cats but can cause mild distress.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
Slightly ToxicDogs may experience mild gastrointestinal upset if they ingest the roots or stems of Dahlia imperialis. The plant is not highly toxic to dogs but can cause discomfort.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
Slightly ToxicThe roots and stems of Dahlia imperialis contain toxic compounds that can cause mild gastrointestinal distress when ingested. The plant's toxicity is not severe but can lead to discomfort in humans.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Dahlia imperialis suitable for indoor cultivation?
A: No, it is a large, outdoor plant that requires ample space and sunlight.
Q: How tall does Dahlia imperialis grow?
A: It can reach heights of 10–15 feet under optimal conditions.
Q: Does Dahlia imperialis require staking?
A: Yes, due to its height and woody stems, staking is recommended to prevent wind damage.
Quick Reference
| Family: | Asteraceae |
| Care: | moderate |
| Light: | partial shade to full sun |
| Water: | every 5–7 days during active |
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