Purple loosestrife – planting, care and tips

Purple loosestrife (Lythrum salicaria)
Purple loosestrife (Lythrum salicaria)

It bears bright dark pink flowers, magically attracts butterflies and bees, contains healing powers, has an uncomplicated disposition and loves damp, wet places. No wonder that the purple loosestrife steals the show in many gardens.

Profile of purple loosestrife:

Scientific name: Lythrum salicaria

Plant family: loosestrife family (Lythraceae)

Other names: spiked loosestrife, purple lythrum

Sowing time: Spring (self-seeding)

Planting time: March to April and September to October

Flowering period: July to September

Harvest time:

Location: sunny to partially shaded

Soil quality: loamy, calcipholous, nutrient rich, humus rich

These information are for temperate climate!

Use as a medicinal herb: bleeding gums, skin inflammation, indigestion, sore throat, and many more

Use in: flower beds, bouquets, pond planting, flower garden, natural garden, water garden

Winter hardiness: hardy, USDA Plant Hardiness Zones: 3

Bee and insect friendly: Yes

Plant characteristics and classification of purple loosestrife

Plant order, origin and occurrence of purple loosestrife

The purple loosestrife (Lythrum salicaria) is native to Europe and Asia. It was naturalized in North America in the 19th century and took the continent by storm. However, the wild perennial from the loosestrife family (Lythraceae) spread there so much that in many places it is on sufferance and sometimes even fought. The common loosestrife in North America has been shown not to displace native plant species, and it is also a source of food for many insects. In the wild, the deciduous and robust plant grows on the edge of streams or ditches and within wetlands and waters.


Purple loosestrife is an invasive species in Canada and the U.S. and has spread widely. It outcompete with natural plants and you should therefore take care off, that plants from your garden do not escape. For this, cut off withered blossoms in time, before the seeds ripen. For medicinal use, you can cultivate other herbs which have similar properties. Best is to not plant the flower in your garden, if you live in North America.

Characteristics of purple loosestrife


With its 100 to 120 centimeters (40 to 48 in) high, bushy stature, the common loosestrife is a very large wild perennial. The edged, persistent stems are partially branched and grow from a rhizome. With age, the stems become woody on the bottom.


The stemless leaves either sit as three whorls, two opposite each other and alternate on the stem. They are lanceolate to oval in shape and have a rounded to heart-shaped leaf base. The narrow leaf blades are softly hairy and the leaf veins emerge clearly below.


The bright dark pink flowers of the purple loosestrife are not only a feast for the eyes, they also attract many bees and butterflies to the garden. The flowers open from July to September in the form of a narrow pseudospiklet at the ends of the stable stems.


In late summer, purple loosestrife carries egg-shaped capsules three to four millimeters (0.12 to 0.16 in) long.

Purple loosestrife – cultivation and care


The impressive perennial prefers a partially shady to sunny location in the garden. If the purple loosestrife gets a shady place, the beautiful flowers cannot develop optimally. In addition, the plant needs a lot of water, so a location on the shore, near a garden pond or a place with a high groundwater level is ideal. The perennial tolerates direct sunlight as well as waterlogging, but it also tends to overgrow. The plant should therefore be given sufficient space.

The Lythrum salicaria is also a plant that is ideal for garden and swimming ponds. If it gets its position in the water, however, it must be ensured that the distance between the water and ground is only about 10 cm (4 in).

The beautiful perennial has a water-cleaning effect. But be careful! If the purple loosestrife feels too comfortable in the garden pond, it begins to propagate and can also spread up to 150 cm (5 ft.) in the pond.


The purple loosestrife is quite undemanding and easy to care for. It prefers nutrient-rich, moist, slightly basic and even loamy soil. It can also be planted in ordinary garden soil mixed with compost and mulch. Because both have the property of storing water, which is then gradually released into the soil. But even if the plant receives sufficient moisture, it is important to water it regularly.

If you choose the location of the plant in the water, you can use classic pond soil that is filled into a bowl, basket or container.

Purple loosestrife
Purple loosestrife


In the bed

The best time to plant purple loosestrife is in spring from March to April and in addition to it from September to October. The planting distance should be 30 cm to 40 cm (12 to 16 in). The planting hole, on the other hand, is excavated so large that a mixture of peat and soil can still be filled in around the root ball. When the perennial is planted, the soil is pressed on firmly and well watered. If the perennial has no leaf crest, then it is only covered with about 1 cm to 3 cm (0.4 to 1.2 in) of soil. Sometimes a crusty surface forms after drying, which is loosened carefully.

In the pond

If the flowering perennial is intended for the pond or a watercourse, it is planted directly in a bowl or a basket suitable for ponds from May to June. It is important that this vessel has a suitable size because the plant can also reach a considerable width and an impressive height in water. The procedure for proper planting in the pond is as follows:

  • line the basket with jute
  • fill in special pond soil
  • insert the plant and fill up with soil
  • add fertilizer ball
  • cover with jute, straw and a layer of gravel
  • place the basket now max. 20 cm (8 in) deep or close under the water surface


In a sunny place in the garden, the purple loosestrife needs above all a lot of and regularly water, because with this perennial the soil must never dry out completely. For this reason, the plant should be supplied with water several times a day in midsummer. In addition to stagnant tap water and rainwater, pond water is also suitable for watering. Plants or perennials in the water that receive groundwater do not need to be watered additionally.

A layer of bark mulch, which is spread around the plant, can protect it both from drying out and from evaporation.


An important factor for the growth and flowering of the purple loosestrife is, in addition to regular watering, the annual fertilization in spring. Ideally, a long-acting perennial fertilizer should be used. Mineral fertilizers from specialist shops or organic fertilizers such as horn shavings or compost can be used. Alternatively, plant swill from grass clippings and nettles or compost, which is added to the soil, is also suitable.

However, the fascinating perennial must not be over-fertilized and under no circumstances should it contain too much nitrogen.


The frugal perennial does not require much care. In spring, the purple loosestrife is pruned in the bed or as a culture in the pond a hand’s breadth above the ground to ensure healthy new shoots. If self-seeding is to be prevented, the faded parts of the plant should be cut off after the main bloom in autumn. These can then be cut into small pieces as mulch or for composting.


The perennial propagates by self-seeding in spring when the shoots have not been cut and the seeds fall out of the spikes. The purple loosestrife can also be propagated by cuttings in summer or by division. If the propagation takes place by division, the perennial is first excavated from the ground. Then the roots are divided in the middle and then re-planted again.

If there is no division of the perennial, the plant can remain at the same location for a period of 10 to 20 years, where it will develop into a fine specimen over time.

Diseases and pests

It is a strong and insensitive perennial in which diseases and pests occur very rarely. Nevertheless, Lythrum salicaria can be affected by leaf spot disease. With this bacterial disease, dark, black and sharply rimmed spots appear on the lower and upper leaf side. The leaves first turn brown and then dry up. The disease is favored primarily by high soil moisture and rain. If the infestation is severe, the affected plants should be removed and put into the garbage not the compost. However, if only a few leaves are affected by the leaf spot disease, they can simply be plucked.


The robust purple loosestrife is a winter-proof perennial that does not require special winter protection when planted in a bed. Plants that are in the water should be taken out of the pond in a very harsh winter and move into winter quarters. For example, it can winter in a bucket that is stored in a frost-free room such as the basement, the stairwell or the garage. Another option is to take the perennial out of the water before the first frost and plant it in the ground.

Use in the garden

The hardy, perennial is especially in combination with monkey flowers (Mimulus), aconite (Aconitum), spiderworts (Tradescantia), bluebuttons (Knautia arvensis) or the astilbe a real eye-catcher in the herbaceous border. The purple loosestrife forms a wonderful flower ensemble with tall grasses such as switchgrass (Panicum virgatum), sword grass (Miscanthus) or the small reed (Calamagrostis). A high-contrast play of colors can also be created together with sunflowers.

In the pond, on the other hand, other moisture-loving perennials such as daggers (Iris pseudacorus) and the dotted loosestrife (Lysimachia punctata) are suitable as accompanying plants. While the shoots of the impressive plant are ideal as cut flowers for the vase, the already faded stands can be used as dried flowers. If the spike remain in the garden during the winter, the remaining seeds can serve as feed for the birds.

Purple loosestrife as a medicinal herb

It is hardly used in medicine, despite its diverse healing effects. As its name suggests, purple loosestrife is hemostatic and also helps against diarrhea. Its antitussive effect and its abilities for skin diseases make it a good all-round medicinal plant.

Diarrhea, even for children

Since it has a mild effect, it can also be used for small children, for example if they have diarrhea. It not only has a diarrheal effect, but also antibiotic against pathogens in the intestine. It is even said to have a beneficial effect against typhoid.

Hemostatic effect

The purple loosestrife has its name from the hemostatic effect. Drunk as a tea, it can even stop slight internal bleeding. Of course, if you have internal bleeding, you should definitely see a doctor and if the bleeding is severe you should go to the hospital.

Heavy menstrual bleeding can also be relieved by purple loosestrife tea. Powdered it helps against heavy nosebleeds. The stems can be chewed against bleeding gums.

Lowering blood sugar

Purple loosestrife tea or tincture can also have a beneficial effect on diabetes because it lowers blood sugar slightly. Of course, you should treat diabetes primarily with diet, exercise and medically prescribed medication. Herbs that lower blood sugar can only support the treatment.

External application

Applied externally as a wash or envelope, it helps with eczema, itching and wounds. It not only has a healing effect on skin inflammation, it also fights pathogens. If you have a sore throat, you can gargle with purple loosestrife tea and rinse your mouth if you have sore mouth. As a sitting bath, an infusion helps against vaginal infections.

Purple loosestrife can be used for these ailments and diseases

  • bleeding gums
  • cough
  • diabetes (supportive)
  • diarrhea
  • eczema
  • heavy menstrual bleeding
  • impetigo
  • indigestion
  • internal bleeding (slight)
  • itch
  • lowering blood sugar
  • nosebleeds
  • skin inflammation
  • sore throat
  • vaginal inflammation
  • wounds

Medicinal properties

  • antibacterial
  • astringent
  • hemostatic

Side effects

Not known.


Ask your doctor or pharmacist. Visiting this page can not replace the visit to the doctor. For serious or unclear complaints, consult your doctor.


  1. Please do not encourage planting Purple Loosestrife. This is a noxious pandemic of an invasive plant in North America, and is not indigenous. It spread to Wisconsin from Europe or Asia in the early 1800s. If desired for folk remedies, I recommend volunteering to wade into marshes on weed patrol since each plant and root have to be removed to stop the millions of tiny viable seeds from each plant from overwhelming native species especially edibles such as “Ratroot” (native Cattails) and driving away wildlife. https://www.invasivespeciescentre.ca/invasive-species/meet-the-species/invasive-plants/purple-loosestrife/

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