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Photos: Wikimedia Commons
Dahlia
Care at a glance
Light
Water
Humidity
Temperature
Growth
Soil
Fertiliser
Pet safety
About this plant
Native to Mexico, dahlias grow from tubers and flower from midsummer until the first frost. There are thousands of varieties. Compact border dahlias suit pots; tall types need staking. The more you pick, the more they flower.
Best spots
Sunny balconies (dwarf varieties in pots), cutting gardens and borders.
Plant facts
| Botanical name | Dahlia hybrids |
| Family | Asteraceae |
| Origin | Mexico & Central America |
| Plant type | Tuberous perennial |
| Mature size | 30 cm–1.5 m+ |
| Growth rate | Fast |
| Foliage | Divided green or dark bronze leaves |
| Flowers | Many forms and colours |
| Toxicity | Mildly toxic to pets |
| Propagation | Tuber division or cuttings |
Seasonal care calendar
Based on Southern Hemisphere seasons.
Troubleshooting
| Holes in leaves and flowers | Earwigs or snails. Trap or use pet-safe bait. |
| White powder on leaves | Powdery mildew. Improve airflow. |
| Tubers rot | Too wet. Plant in free-draining soil and wait for shoots before watering. |
| Tall, floppy stems | Stake early and pinch the tips. |
| Few flowers | Not enough sun or not deadheaded. |
Common questions
Should I pinch dahlias?
Yes. Pinch the tip when plants are about 30 cm tall for bushier plants and more flowers.
Do I need to lift tubers?
In cold or wet winters, yes. In mild, dry areas they can stay in the ground.
Can they grow in pots?
Yes, choose dwarf or border types.
How do I make cut flowers last?
Pick in the cool of the morning and put stems in hot water for an hour.
