Astra White
Astra White is a compact cultivar of Platycodon grandiflorus producing clean white, star-shaped flowers that open from inflated buds. It performs best in full sun to light shade with moist but well-drained soil. The tidy mound suits rock gardens, containers, and front-of-border placements. Flowering peaks in midsummer in much of North America.
At‑a‑glance
Group/Class: Astra Series; dwarf selection
Height × spread: 8-12 in (20-30 cm) × 12-20 in (30-50 cm)
Bloom window: mid July to late August
Color & flower form: white; single, star-shaped from balloon buds
Fragrance: 0 none
USDA hardiness: zones 3-8
Breeder / Year / Origin: unknown
Cut-flower notes: short stems; sear cut ends; use for small arrangements
Pet safety: unknown
How it differs
- Compact size compared with standard strains.
- White blossoms offer contrast to the usual blues and pinks.
- Less prone to flop in summer than tall cultivars.
- Height can vary among seed-grown plants.
Strengths
- Bright white color for mixed plantings.
- Good container and edging habit.
- Hardy and adaptable in average garden soils.
- Low pest and disease pressure.
Care in one minute
Light: full sun to light shade.
Soil: fertile, well-drained; slightly acidic to neutral.
Water: steady moisture; avoid standing water.
Feeding: light spring fertilizer is adequate.
Grooming: deadhead; light pinch or trim in late spring to maintain shape.
Winter: mulch lightly; mark clumps to protect late-emerging shoots.
Watch‑outs
- Wet or heavy soils can cause root problems.
- Late spring emergence increases risk of accidental disturbance.
- Resents division once established.
Best uses (tags)
containers, edging, borders, rock gardens, cutting
Provenance note
Part of the Astra seed series selected for compact, container-friendly plants. RHS lists ‘Astra White’ at about 30 cm tall in UK conditions.
References
- RHS – Platycodon grandiflorus ‘Astra White’ cultivar profile
- Missouri Botanical Garden – Platycodon grandiflorus (Plant Finder)
- Chicago Botanic Garden – Platycodon cultivar trial notes (general)
- NC State Extension – Platycodon grandiflorus profile
Written by: Your Flowers Guide editorial team
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