Dahlias in Freemantle

Dahlia pinnata

Dahlia
Dahlia · 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.

100 cm · Full Shade · High Water

Add to garden

Calibrated to Freemantle · last frost ≈ 20 Apr

Sow indoors March, plant out April to May. Frost risk November to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoNoYesNoNoNoNoNoNoNoNoNo
Plant outNoNoNoYesYesNoNoNoNoNoNoNo

Growing guide

Step-by-step instructions for growing Dahlia

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. 01

    Start Tubers Indoors

    9 Mar to 23 Mar

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

  2. 02

    Pot On Shoots

    6 Apr to 13 Apr

    Once shoots are tall, pot each tuber into individual containers with multi-purpose compost from 6th April - 13th April. Grow on in a bright, frost-free place.

  3. 03

    Harden Off Plants

    27 Apr to 4 May

    Gradually acclimatise plants to outdoor conditions over 10-14 days from 27th April - 4th May. Place outside during the day and bring in at night, avoiding frost.

  4. 04

    Plant Outdoors

    4 May to 18 May

    Transplant into well-drained, fertile soil in full sun after frosts from 4th May - 18th May. Space plants apart and water in well. Use fleece if cold nights are forecast.

  5. 05

    Support and Pinch

    18 May to 25 May

    Insert stakes at planting to support tall stems. Pinch out the growing tip when plants reach to encourage bushiness from 18th May - 25th May.

  6. 06

    Feed and Water

    25 May to 22 Oct every 2 weeks

    Water regularly to keep soil moist, especially in dry spells. Feed every 14 days with a high-potash fertiliser from 25th May to boost flowering. Stop feeding by 22nd October.

  7. 07

    Deadhead Regularly

    6 Jul to 29 Oct

    Remove spent flowers weekly from 6th July to encourage continuous blooms. Cut back to a leaf joint to promote new buds.

  8. 08

    Lift and Store Tubers

    12 Nov to 26 Nov

    After the first frost blackens foliage, cut stems back and carefully lift tubers from 12th November - 26th November. Dry, label, and store in frost-free conditions in dry compost or sand over winter.

Companion plants

Tap a plant to see why it works (or doesn't) with Dahlia.

Good companions

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

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.

Dahlia guides by town

See how Dahlia timing shifts in other towns with different frost dates.