Dahlia

Dahlias in York

Dahlia pinnata

Show-stopping tuberous perennials that provide a spectacular display of colour from mid-summer right up until the first frosts. Ranging from enormous 'dinner plate' blooms to intricate pompoms and open-centred varieties that bees adore, they are a staple of the late summer UK garden.

Height100cm
SunlightFull Shade
WaterHigh Water

Growing Guide

Step-by-step instructions for growing Dahlia

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Growing Guide for

Change the guide to see different planting timelines and tips.

The most common UK method, starting tubers indoors in spring and planting out after frosts for summer blooms.

1
Start Tubers Indoors

23 Feb - 9 Mar

Place tubers in trays with moist compost, eye-side up, and cover lightly. Keep at in a bright spot indoors from 23rd February - 9th March. Water sparingly until shoots appear.

2
Pot On Shoots

23 Mar - 30 Mar

Once shoots are tall, pot each tuber into individual containers with multi-purpose compost from 23rd March - 30th March. Grow on in a bright, frost-free place.

3
Harden Off Plants

13 Apr - 20 Apr

Gradually acclimatise plants to outdoor conditions over 10-14 days from 13th April - 20th April. Place outside during the day and bring in at night, avoiding frost.

4
Plant Outdoors

20 Apr - 4 May

Transplant into well-drained, fertile soil in full sun after frosts from 20th April - 4th May. Space plants apart and water in well. Use fleece if cold nights are forecast.

5
Support and Pinch

4 May - 11 May

Insert stakes at planting to support tall stems. Pinch out the growing tip when plants reach to encourage bushiness from 4th May - 11th May.

6
Feed and Water

24 Oct - 11 May
every 2 weeks

Water regularly to keep soil moist, especially in dry spells. Feed every 14 days with a high-potash fertiliser from 24th October to boost flowering. Stop feeding by 11th May.

7
Deadhead Regularly

31 Oct - 22 Jun

Remove spent flowers weekly from 31st October to encourage continuous blooms. Cut back to a leaf joint to promote new buds.

8
Lift and Store Tubers

14 Nov - 28 Nov

After the first frost blackens foliage, cut stems back and carefully lift tubers from 14th November - 28th November. Dry, label, and store in frost-free conditions in dry compost or sand over winter.

Companion Plants

Plants that grow well (or poorly) with Dahlia

Why Companion Planting Matters

Companion planting can help deter pests, improve pollination, enhance growth, and maximize garden space. Some plants release chemicals that repel pests or attract beneficial insects, while others can improve soil quality or provide shade for sensitive plants.

Suggested Varieties

Popular varieties of Dahlia to consider

Bishop of Llandaff

A classic variety with dark foliage and bright red flowers, ideal for borders and excellent for pollinators.

Café au Lait

Popular for weddings, with large, creamy-pink blooms that can reach up to 25cm across.

Happy Days

A compact bedding type, perfect for containers, with prolific flowering in mixed colours.