How and when to plant dahlias
Dahlias are spectacular garden flowers, admired for their large, colourful blooms that brighten up borders from summer until late autumn. Native to Mexico, they thrive in warmth and sunshine. For long-lasting flowering and healthy growth, it is essential to plant them correctly and at the right time.
When is the best time to plant dahlias?
Dahlias are planted in spring, after the risk of frost has passed, usually in April–May. Tubers need warmed soil and temperatures above 10 °C to start growing. In colder regions, it is advisable to start tubers in pots indoors and transplant them outside once the weather has warmed.
Where to plant dahlias
Dahlias prefer sunny spots where they receive at least six hours of direct light per day. The soil should be fertile, loose and well-drained. In heavy or clay soils, improve drainage by adding sand or compost.
How to plant dahlias step by step
- Dig a hole about 15 cm deep.
- Place the tuber in the hole with the neck facing upwards, where the new shoots will form.
- Cover lightly with soil, keeping it loose so that the shoots can emerge easily.
- Water moderately after planting and increase watering as the plant develops.
- Plant tubers 40–60 cm apart, depending on the variety.
Aftercare
- Water regularly, especially in hot, dry periods, but avoid waterlogging.
- Apply mulch to retain soil moisture and suppress weeds.
- Fertilise monthly with a feed for flowering plants.
- Deadhead spent blooms to encourage continuous flowering.
- Before winter, lift the tubers, dry them, and store in a cool, dry place until the next season.
Summary
Dahlias are best planted in spring, once frost danger has passed, in a sunny position with fertile, well-drained soil. With proper planting and care, these spectacular flowers will fill your garden with colour and life from summer through to late autumn.
