Dahlias in Edinburgh

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 Edinburgh · last frost ≈ 4 May

Sow indoors March, plant out May to June. Frost risk October to May.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoNoYesNoNoNoNoNoNoNoNoNo
Plant outNoNoNoNoYesYesNoNoNoNoNoNo

Growing guide

Step-by-step instructions for growing Dahlia

Growing guide for

Change the guide to see different planting timelines and tips.

Growing dahlias from seed for bedding varieties, sown indoors in early spring for summer flowers.

  1. 01

    Sow Seeds Indoors

    9 Mar to 23 Mar

    Sow seeds thinly on the surface of moist seed compost in trays from 9th March - 23rd March. Cover lightly and keep at in a bright spot. Germination takes 7-14 days.

  2. 02

    Prick Out Seedlings

    30 Mar to 6 Apr

    Once seedlings have true leaves, transplant into individual pots from 30th March - 6th April. Handle by leaves to avoid stem damage and grow on in good light.

  3. 03

    Harden Off Plants

    11 May to 18 May

    Acclimatise plants to outdoors over 10-14 days from 11th May - 18th May. Increase exposure gradually, protecting from frost and strong winds.

  4. 04

    Plant Outdoors

    18 May to 1 Jun

    Transplant into beds or containers after frosts from 18th May - 1st June. Space apart in full sun and water well. Use cloches if needed for early planting.

  5. 05

    Pinch for Bushiness

    8 Jun to 15 Jun

    Pinch out the growing tip when plants are tall from 8th June - 15th June to encourage side shoots and more flowers.

  6. 06

    Water and Feed

    15 Jun to 2 Oct every 2 weeks

    Keep soil consistently moist. Feed with a balanced liquid fertiliser every 14 days from 15th June to support growth and flowering until 2nd October.

  7. 07

    Deadhead Flowers

    3 Aug to 9 Oct

    Remove faded blooms regularly from 3rd August to prolong flowering. Snip off just above a leaf node to encourage new buds.

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.