What soil does Dahlia grow in?

It tolerates these soils: average garden soil.

Hardy down to -12 °C (USDA zone 8, RHS H5). Outdoors in this country it only survives with winter protection, or in a pot overwintered frost-free.

When does Dahlia flower?

Flowering: July–October, white, yellow, orange, red, pink, purple.

How much water does Dahlia need?

Water need: medium. Drought tolerance: low.

Dahlia

Dahlia × hortensis

Dahlia (Dahlia × hortensis) is a perennial. Light: full sun, part shade. Hardy down to -12 °C. Drought tolerance: low. Toxic to dogs and cats.

Illustration of Dahlia — An illustration of the typical shape of the mature plant, not a photo.

What it's good for, and what it isn't

It does not overwinter outdoors here: the tubers must be lifted after the first frost and stored frost-free. It flowers from midsummer until the frosts and is an excellent cut flower; cultivars range from 30 cm bedding types to 1.5 m dinner-plate giants, so check the mature height and flower form when choosing (single-flowered ones feed pollinators, tall ones need staking). Plant the tubers once spring frosts are over, around mid May, in a sunny spot with rich, well-drained soil and water regularly in summer. When the first frost has blackened the foliage, cut the stems back to 10 to 15 cm, lift the tubers, let them dry, then keep them in dry sand, peat or sawdust at 4 to 7 °C in a frost-free place and replant in spring.

Watch out for

Tubers freeze in the ground, rot in damp storage and shrivel if kept too dry. Slugs eat the young shoots and earwigs the flowers; aphids, spider mites and powdery mildew are also common. Discard plants with virus symptoms (mosaic, distorted leaves), as they cannot be cured. Tall, large-flowered cultivars flop or snap in wind without staking.

Key facts

Light: Full sun, Part shade
Water need: Medium
Care: High
Size after 10 years: 1 m × 60 cm
Hardiness: down to -12 °C
Foliage: Deciduous
Flowering: J F M A M J J A S O N D July–October, white, yellow, orange, red, pink, purple

All details

Group	Perennial
Light	Full sun, Part shade
Size after 10 years	1 m × 60 cm
Ultimate size	0.3–1.8 m × 30–90 cm
Hardiness	down to -12 °C (USDA 8, RHS H5)
Soil	Average garden soil
Foliage	Deciduous
Flowering	July–October, white, yellow, orange, red, pink, purple
Water need	Medium
Drought tolerance	Low
Maintenance	High
Root aggressiveness	Low
Suckering	no data
Spreading	Low
Distance from buildings	no data
Distance from paving	no data
Litter	not typical
Planting distance	50 cm
For dogs	Toxic
For cats	Toxic
For children	Mildly toxic (uncertain)
Typical price	no data

Toxicity data is for information only. If your pet or child has eaten a plant, contact a vet or a doctor.

Frequently asked questions

Data updated: October 17, 2026 · How our data is made

Appears in these lists

Perennials for part shade Perennials for full sun Perennials for pollinators Plants for containers

Looks good next to it

Montbretia

Crocosmia × crocosmiiflora

Chinese silver grass

Miscanthus sinensis

English holly

Ilex aquifolium