Allium 'Atlas'

RHS Plant Profile

allium 'Atlas'

RHS

Bulbs

Bulbous perennial growing to a height of around 1.2m. Large, rounded heads of purple star-shaped flowers with green centres are produced on strong, erect stems from May until June. Ideal as a cut flower, both fresh and dried

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

1-1.5 metres

Max Spread

0-0.1 metre

Size

Time to Maturity: 2–5 years
Max Spread: 0-0.1 metre
Max Height: 1-1.5 metres

Growing Conditions

Chalk Loam Sand

Moisture: Moist but well–drained or Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: South–facing or West–facing
Exposure: Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H4

Colour & Scent

Fragrance Foliage

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Amaryllidaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Clump forming
Genus: Allium are bulbous herbaceous perennials with a strong onion or garlic scent, linear, strap-shaped or cylindrical basal leaves and star-shaped or bell-shaped flowers in an umbel on a leafless stem
Name Status: Accepted

How to Grow

Cultivation

Grow in fertile, well-drained soil. Add grit to clay soils to improve drainage. Care should be taken in colder regions to mulch or plant in pots and move to a frost-free location See allium cultivation

Propagation

Propagate by division: once flowering is over and leaves have died down, lift the bulbs, detach any offsets, and plant them in their final positions or grow on first in gritty compost

Suggested planting locations and garden types

City and courtyard gardens
Cottage and informal garden
Gravel garden
Patio and container plants
Wildlife gardens
Cut flowers
Flower borders and beds

Pruning

No pruning required

Pests

Generally pest-free

Diseases

May be susceptible to onion white rot and downy mildews