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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:
This plant will provide nectar and pollen for bees and the many other types of pollinating insects.
It is included in an evolving list of plants carefully researched and chosen by RHS experts. Divided into 3 groups these lists, linked below, are maintained by a team of RHS staff and are reviewed annually.
Other common names
allium 'Purple Giant'
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
'Purple Giant' is a bulbous herbaceous perennial, up to about 75cm high, with linear green leaves which start to die down when the dense, spherical umbels, about 25-30cm across, of purplish-pink flowers appear in summer
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 West-facing or East-facing
MoistureMoist but well-drained, Well-drained
SoilChalk, Loam, Sand
pHAcid, Alkaline, Neutral
Time to ultimate height
Grow in full sun in a sheltered position in well-drained soil; for more advice see Allium cultivation
Propagate by offsets: once flowering is over and the leaves have died down, lift the bulbs, detach the offsets, plant larger ones where you want them to grow, and grow smaller ones in gritty compost before planting out; for more advice see bulb propagation
Suggested planting locations and garden types
Cut Flowers Flower borders and beds Drought Resistant Low Maintenance
City & Courtyard Gardens Gravel Garden Patio & Container Plants Cottage & Informal Garden
Pruning No pruning required
Pests May be affected by onion fly, allium leaf mining fly, slugs and snails
May be affected by onion white rot and a downy mildew
RHS members can get exclusive individual advice from the RHS Gardening Advice team.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.