Centaurea 'Amethyst on Ice'
Knapweed, Star thistle
- Height × spread
- 0.5m × 0.4m
- Position
- Full sun
- Hardiness
- Very cold to -20C (RHS H6)
- Flowers
- Spring, Summer
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This has showy knapweed blooms that are spring and early summer flowering. Each flower has a vivid, rather spiky-looking central zone full of slender upright petals coloured near black and vivid-red-purple. There are white tints at their base. The outer ring of petals are jagged and vivacious in their effect with slender stems that flare into an informal fan-shape of snowy-white petals. The flowers open from green, brown edged buds and are accompanied by large pale green leaves. General: If cut back when the flowers have finished there may be fresh foliage and a further show in autumn.
- Flower colour
- Purple, White
- Foliage colour
- Green
- Variegated
- No
- Scent
- No
- Shape
- Bell
- Height
- 0.5m
- Spread
- 0.4m
- Season of interest
- Spring, Summer
- Flowers in
- Spring, Summer
- Evergreen
- Deciduous
- Garden style
- Seaside garden, Cottage garden
- Sun or shade
- Likes full sun
- Soil type
- Loam (normal)
- Soil pH
- All types
- Drainage
- Moisture retentive soil, Well drained soil
- Hardiness
- Very cold to -20C (RHS H6)
- Borders & containers
- Borders
- Use for
- Bee attraction, Butterfly attraction
- Hazards
- No
Spring
Spring-Autumn · Outdoors
Water in dry periods
Established plants in the ground can cope with 7-10 days of dryness, and shrubs often manage 2 to 3 weeks. Water one section of the garden thoroughly each day rather than a little everywhere. Check plants in pots more often, especially in hot weather.
Spring-Summer · Planting
Prune after flowering
When flowering has finished, cut the plant hard back removing all stems to buds that are 30cm to 45cm above ground level.
Summer
Summer - early · Outdoors
Feed a general fertiliser
Where plants have moderate needs for nutrients, they can simply be given a general feed, fairly early in the growth season so that the growth has plenty of time to harden off before the cold weather.
Give plants a general boost with the application of a general purpose fertiliser which is spread around the root area of the plant, with amounts as directed on the feed label.
Found in
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