How to Grow Lythrum Plants in your Garden

Gardener's HQ Guide to Growing Loosestrife and Purple Willow Herb

Lythrum plants are hardy perennials. They can reach an height of 150 cm (5 feet).

Be aware that they are an invasive species in many areas in Northern America, and growing them is banned in the garden in many areas.

This is to help with control of these plants in native wetland areas.

Lythrum salicaria
Lythrum salicaria by Ettore Balocchi.

In areas where it can be grown non-invasively, it makes a useful pond edge plant. When in bloom it carries purple-red flowers.

Lythrum alatum
Lythrum alatum - Winged Loosestrife by bob in swamp.

Commonly Grown Lythrum Species Photographs and Plant Identification

Lythrum alatum

Lythrum alatum
Lythrum alatum (Winged Loosestrife), photograph by Frank Mayfield; CC.

Lythrum hyssopifolia

Lythrum hyssopifolia
Lythrum hyssopifolia (Hyssop Loosestrife / Grass-poly), photograph by Doug Beckers; CC.

Lythrum salicaria

Lythrum salicaria
Lythrum salicaria (Purple Loosestrife / Spiked Loosestrife), picture by Andreas Rockstein; CC.

Lythrum Plant Growing and Care Guide

Common Names: Loosestrife, Purple Loosetrife, Purple Willow Herb, False grass-poly, Red Sally.
Life Cycle: Hardy perennial.
Height: 24 to 60 inches (60 to 150 cm).
Native: Asia. Australasia. Africa. Europe.
Family: Lythraceae.
Growing Region: Zones 3 to 9.

Flowers: Summer through to early autumn.
Flower Details: Pink, purple-red. Spikes. Six petals.
Foliage: Herbaceous. Lance-shaped. Oblong. Broad. Downy.

Sow Outside: Cover seed. Start of spring - before the last frost, or towards the end of autumn. Spacing 18 to 36 inches (45 to 90 cm).
Sow Inside: Germination time: one week to one month. Temperature: 65 to 70°F (18 to 21°C). Seven or eight weeks in advance. Transplant outdoors following the last frost.

Requirements and care: Full sunlight or partial shade. Soil pH 5.0 to 7.0. Wet to moist soil. Deadhead to prevent seed set and to keep tidy. Divide every coupl of years to aid in control. Propagate: Self seeds readily. Or by dividing at the beginning of spring.

Miscellaneous: Can grow incredibly invasively, and growing it is banned in many areas; the plant is usually controlled by the use of beetles. Lythrum is also a food plant for many Lepidoptera members including the Emperor moth and the V-pug. Used to treat diarrhea and dysentery.

The Gardener's HQ Guide to Growing and controlling Lythrum Plants

I hope that you found this guide on how to identify Lythrum plants useful. You may also enjoy my gardening guides on how to grow Gloriosa-lily, Asclepias syriaca and Lima Bean plants.