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We have combined these two powerful search tools into a single Find a Plant service searching over 250,000 plant records.
Virtually all of the features of the old searches are still available and in addition we have added several new features to create a more comprehensive and user friendly search experience.
When using this search
Search by plant name, key attributes or both to find plant details and a list of
AGM plants have been through a rigorous trial and assessment programme. They are:
© RHS 1999
the RHS today and get 12 months for the price of 9
Other common names
giant onion giant allium
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
A. giganteum is a perennial with spreading, glossy, strap-shaped basal leaves which die down before the flowers. Dense globose umbels of bright purple flowers are borne on tall stems in summer
C Asia to NE Iran
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
Aspect South-facing or North-facing or West-facing or East-facing
MoistureWell-drained, Moist but well-drained
SoilChalk, Clay, Sand, Loam
pHAcid, Alkaline, Neutral
Time to ultimate height
Easy to grow in fertile well-drained soil. Add grit when grown in clay soils to improve drainage
Propagate by seed, sowing in containers in a cold frame when just ripe or in the spring. Alternatively, remove offsets in autumn
Suggested planting locations and garden types
Flower borders and beds Cut Flowers
Cottage & Informal Garden
Pruning No pruning required
Pests Generally pest free
Generally trouble-free: Onion white rot and a downy mildew may occur
RHS members can get exclusive individual advice from the RHS Gardening Advice team.
Buy from £3.99
at the RHS Plants Shop
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Join the RHS today and get 12 months for the price of 9