Overview
Lythrum salicaria 'Swirl' is a clump forming perennial in the genus Lythrum, part of the Lythraceae family, with deciduous foliage. It typically grows around 1.0 m tall. Lythrum salicaria 'Swirl' grows best in full sun, and tolerates clay and loam soils and any pH. Its UK hardiness is rated H7. Suggested uses include cottage and informal garden, wildlife gardens, wildflower meadow and flower borders and beds. It is native to Europe and Asia.
About
Lythrum salicaria 'Swirl' is an herbaceous perennial in the Lythraceae grown for its upright spikes of purple flowers. It forms clumps of deciduous foliage and flowers from July to September. Suited to full sun and moist soils, it tolerates both well-drained and poorly drained conditions. The cultivar performs well in south- or west-facing positions in exposed or sheltered sites.
About the genus
Lythrum is a genus of 38 species of flowering plants native to the temperate world. Commonly known as loosestrife, they are among 32 genera of the family Lythraceae.
Wikipedia contributors, "Lythrum", CC BY-SA 4.0 — Lythrum
In the garden
Lythrum salicaria 'Swirl' belongs to the family Lythraceae and is an herbaceous perennial native to temperate regions. It carries the common name purple loosestrife and produces long, upright flower spikes that appear in mid to late summer, reliably flowering from July to September. Place plants in full sun on soils of clay or loam; they handle a wide pH range from acid to alkaline and will tolerate both moist but well-drained ground and poorly drained sites. Choose a south- or west-facing aspect if possible, though the cultivar accepts exposed or sheltered locations. The plant is fully hardy (H7) and dies back to ground level as deciduous growth in winter while returning the following season. Use Lythrum salicaria 'Swirl' in cottage and informal gardens, wildlife schemes and wildflower meadows, or as a bold element in mixed flower borders and beds. Its clump-forming habit gives structure to damp margins and helps support insect life during its July–September flowering period. Leave spent stems where appropriate to benefit overwintering wildlife and to show the plant's character through the season.
Growing conditions
Best soil and position for Lythrum
- Sunlight
- Full sun
- Soil type
- Clay, Loam
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Poorly-drained
- Aspect
- South-facing, West-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H7
Plant details
Lythrum salicaria 'Swirl' size, habit and characteristics
- Plant type
- Perennial
- Habit
- Clump forming
- Foliage
- Deciduous
- Height
- 1.0 m
- Suggested uses
- Cottage and informal garden, Wildlife gardens, Wildflower meadow, Flower borders and beds
- Native to
- Europe, Asia
Care notes
Pruning and caring for Lythrum salicaria 'Swirl'
- Cultivation
- Prefers moist soil and full sun; tolerates wet conditions; divide clumps in spring to maintain vigor.
- Pruning
- Cut back after flowering to encourage fresh growth and maintain shape.
- Propagation
- Division in spring
- Pest resistance
- Slugs and snails
- Disease resistance
- Generally disease-free
Frequently asked questions
How do I grow Lythrum salicaria 'Swirl'?
Prefers moist soil and full sun; tolerates wet conditions; divide clumps in spring to maintain vigor.
Where is the best place to plant Lythrum salicaria 'Swirl'?
Lythrum salicaria 'Swirl' prefers full sun. It suits exposed and sheltered positions.
What soil does Lythrum salicaria 'Swirl' need?
Lythrum salicaria 'Swirl' grows best in clay and loam soil. It is happy in soil of any pH. Aim for soil that stays moist but well-drained to poorly-drained.
How do I prune Lythrum salicaria 'Swirl'?
Cut back after flowering to encourage fresh growth and maintain shape.
How big does Lythrum salicaria 'Swirl' grow?
Lythrum salicaria 'Swirl' reaches a height of 1.0 m.
Is Lythrum salicaria 'Swirl' hardy in the UK?
Lythrum salicaria 'Swirl' has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Lythrum salicaria 'Swirl'?
Division in spring.
