Product specifications and features

Product Description

Lythrum salicaria - Purple Loosestrife, Native Pond Marginal Plant

Lythrum salicaria, known as purple loosestrife, is a tall UK native wild flower of reedbeds, fens, marshes and riverbanks. Through the summer it carries dense spikes of vivid purplish-pink to magenta flowers.

Purple loosestrife at a glance

Botanical name Lythrum salicaria
Common name Purple loosestrife
Plant type Upright, clump-forming perennial; dies back in winter
Height and spread About 1–1.5 m tall, up to 50 cm wide
Flowers Vivid purplish-pink to magenta, in dense spikes, June to September
Position Full sun
Soil Reliably moist to wet clay or loam; any pH
Pond depth 0–10 cm of water over the crown
Hardiness RHS H7 – very hardy (below -20°C)
Native to UK and Ireland (native wild flower)

Is purple loosestrife good for wildlife?

Yes. It is on the RHS Plants for Pollinators list, and its nectar feeds long-tongued insects such as the brimstone butterfly, red-tailed bumblebee and elephant hawk-moth.

Where to plant it

  • The shallow edge of a wildlife pond, 0–10 cm deep
  • Bog gardens and wet mud
  • A sunny spot

How to plant and care for it

Plant from spring to late summer. Cutting the shoots back in spring reduces its height. Deadhead after flowering to stop self-seeding. Dark speckles on the lower leaves in summer are normal.

Is it invasive?

Not in the UK, where it is native and not restricted, though it self-seeds freely. It is a serious invasive weed in North America, so do not send it abroad. Buy nursery-grown plants rather than collecting them from the wild.

Which size should I buy?

Bare-root plants (7 cm, 9 cm, 1 litre and 3 litre) arrive without a pot or compost and are the most economical way to plant a group. Potted plants (9 cm, 1 litre and 3 litre) arrive growing in our peat-free compost and give a faster display. Packs of 3 come in 7 cm, 9 cm, 1 litre and 3 litre bare-root sizes and cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.