Amaranthus speciosus

RHS Plant Profile
purple amaranth

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purple amaranth visionspictures.com
purple amaranth visionspictures.com

Other common names

prince's feather, red amaranth, showy amaranth

Synonyms

Amaranthus hybridus subsp. cruentus, Amaranthus paniculatus, Amaranthus patulus, Amaranthus speciosus

Annual Biennial

An upright, frost-tender annual with stems to 2m tall clothed with ovate, purple-flushed, dark green leaves and topped with clusters of tiny reddish-pink flowers arranged in upright to arching spikes from summer into autumn

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

1.5-2.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity
1 year
Max Spread
0.1-0.5 metres
Max Height
1.5-2.5 metres

Growing Conditions

Chalk Loam Sand
Moisture
Moist but well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
South–facing or West–facing or East–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)
H2
Drought Resistance
Yes

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Amaranthaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Columnar upright
Genus
Amaranthus can be upright or spreading annuals or short-lived perennials, with simple leaves and tiny flowers borne in dense, erect or pendulous, catkin-like inflorescences in summer and autumn
Name Status
Synonym
Plant Range
Mexico to Nicaragua

How to Grow

Cultivation

Under glass grow in peat-free, loam-based compost in full light. Outdoors grow in moderately fertile, humus-rich, moist soil in full sun in a sheltered site. Water freely during summer to prolong flowering

Propagation

Propagate by seed

Suggested planting locations and garden types

  • Cottage and informal garden
  • Prairie planting
  • Cut flowers
  • Flower borders and beds

Pruning

No pruning required

Pests

May be susceptible to aphids

Diseases

May be susceptible to a virus