Allium validum (swamp onion) — Clump forming

Overview

Allium validum is a clump forming bulbs in the genus Allium, part of the Amaryllidaceae family, with deciduous foliage. Allium validum grows best in full sun, and tolerates most soils and any pH. Its UK hardiness is rated H6. Suggested uses include city and courtyard gardens, cottage and informal garden, gravel garden, patio and container plants, wildlife gardens, cut flowers and flower borders and beds.

About

Allium validum is a species of flowering plant commonly called swamp onion, wild onion, Pacific onion, or Pacific mountain onion. It is native to the Cascade Range, the Sierra Nevada, the Rocky Mountains, and other high-elevation regions in California, Oregon, Washington, Nevada, Idaho and British Columbia. It is a perennial herb and grows in swampy meadows at medium and high elevations. In the garden it prefers full sun and most soil types. In UK gardens it is very hardy across most of the UK (RHS H6). Suggested uses include city and courtyard gardens, cottage and informal garden, gravel garden, patio and container plants, wildlife gardens, cut flowers and flower borders and beds. It tolerates soil of any pH, well-drained conditions and south-facing, west-facing and east-facing aspects. Plant bulbs in autumn in fertile, well-drained soil in full sun. Most are fully hardy and undemanding. Allow foliage to die back naturally.

Wikipedia contributors, CC BY-SA 4.0 — Allium validum

Growing conditions

Best soil and position for Allium

Sunlight: Full sun
Soil type: Chalk, Clay, Loam, Sand
Soil pH: Acid, Alkaline, Neutral
Soil moisture: Well-drained
Aspect: South-facing, West-facing, East-facing
Exposure: Exposed, Sheltered
UK hardiness: H6

Plant details

Allium validum size, habit and characteristics

Plant type: Bulbs
Habit: Clump forming
Foliage: Deciduous
Suggested uses: City and courtyard gardens, Cottage and informal garden, Gravel garden, Patio and container plants, Wildlife gardens, Cut flowers, Flower borders and beds

Care notes

Pruning and caring for Allium validum

Propagation: Offsets, Seed
Pest resistance: Allium leaf miner, Onion fly
Disease resistance: Onion white rot, Onion downy mildew

Frequently asked questions

Where is the best place to plant Allium validum?

Allium validum prefers full sun. It suits exposed and sheltered positions.

What soil does Allium validum need?

Allium validum is adaptable and grows happily in most soil types, including chalk, clay, loam and sand. It is happy in soil of any pH. Aim for soil that stays well-drained.