Description of Lythrum salicaria (Purple Loosestrife)

Lythrum salicaria is purple loosestrife, a wetland perennial with tall spikes of magenta-purple flowers in summer. It’s one of the best plants for adding long-lasting colour to bog gardens and pond edges.

Appearance

It forms upright stems with narrow leaves, then produces dense flower spikes from mid summer. Height is often 1 to 1.5m depending on soil and moisture. Flowers can continue for weeks, especially if you deadhead.

Care Guide

It likes sun and wet ground. In shade it gets lanky and flowers less.

• Sun: Full sun for best flower spikes.
• Soil: Wet, fertile soil or aquatic compost.
• Water: Boggy ground suits it. It also grows at pond edges.
• Deadheading: Snip spent spikes to keep flowers coming and to reduce self-seeding.
• Cut back: Cut stems down in late autumn or late winter.

Divide in spring if clumps get too large. It responds well to being split and replanted.

Suitability for Bog Garden

This is a classic bog garden plant for the back or middle, depending on height. Use it in groups for impact or repeat it along an edge to guide the eye.

It pairs well with pickerel weed and irises, and it provides lots of nectar for insects.

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