The purple loosestrife or Lythrum salicaria, as it is also known under its botanical name, is one of the rather unknown plants for gardens and bouquets. Its spike-shaped flowers are a real splendor and the plant is extremely easy to care for. However, if you want to get the purple loosestrife as an ornament in your own garden, you still have a few things to consider.

Find the optimal location

Banks, moats, swampy areas – the main thing is that they are damp. The purple loosestrife needs large amounts of water all the time. Waterlogging does not cause him any problems, as does direct and strong sun.

The location must therefore be able to serve with a sufficiently high water content and light. The purple loosestrife can tolerate partial shade, but then only shows a few of the impressive flowers. In addition, due to its size, it is unsuitable as underplanting, but can provide a natural privacy screen.

The immediate proximity to a garden pond, watercourse or a place with very high groundwater is ideal. The plant can also stand in water if the distance between the surface of the earth and the water is only about ten centimeters. If the plant cannot be offered this in its own garden, a culture in a tub is the better choice.

Note: The purple loosestrife can reach a height of up to two meters and is then correspondingly massive. The location must therefore also offer a sufficient amount of free space and space upwards. When cultivating in a bucket, choose a container that is as large and heavy as possible.


When it comes to the substrate, the purple loosestrife is particularly easy to care for and undemanding.
Normal garden soil is sufficient. If the Lythrum salicaria is far from water and the substrate cannot be watered constantly, mulch and compost should be mixed in with it. The pieces of mulch and compost fibers store water and gradually release it again. In this way, the soil is supplied with a little moisture even in dry periods. Drying out can be delayed. However, pouring is still necessary, albeit at longer intervals.

If the purple loosestrife is in the water, pond soil is the right substrate. When it is put in a basket or bowl.

Tip: When it comes to the soil for the purple loosestrife, the drier, the more shady. If the soil in the garden tends to dry out and a mixture is not to be used, the plant must be more shady. The more humid the garden, the more sun it can get.


Ideally, the purple loosestrife is planted in the spring, after which the soil has been prepared with compost and mulch.

The planting hole should be adapted to the size of the rootstock. After planting, the soil should be pressed down and the plant should be watered abundantly. However, there are no further steps or special features to be observed.Planting in the water If the purple loosestrife is to be planted directly in a pond or watercourse, pond soil is the substrate of choice. To do this, the rhizome should not be placed loosely on the edge, as it can quickly drift off here. It is better to put it in a bowl or basket and then anchor it in the water. It should be noted that the purple loosestrife can become very tall and extensive and the vessel must have corresponding dimensions. Otherwise, it will tip, topple, or tear out quickly.

The initial watering is of course not necessary when planting in the water.


Depending on the location, regular watering can be the most important maintenance step or it can be completely unnecessary. It is the same with the administration of fertilizer. A cut once a year is then the only measure that has to be carried out under optimal conditions.


If the purple loosestrife is in the water, in a swampy place or over high groundwater, additional watering is of course not necessary. The situation is different if it is otherwise dry. Then, in normal cases, even occasional rainfall is not entirely sufficient. Especially when the location is very sunny.

The substrate should always be kept slightly moist. The purple loosestrife cannot tolerate drying out completely. Daily watering may be necessary in dry, hot summers. This can be remedied by a thick layer of bark mulch, which is spread over the substrate to protect against evaporation.

For casting, the following sources should preferably be used:

  • Rainwater
  • Stale tap water
  • Pond water


As with watering, there is no need to fertilize if the purple loosestrife is planted directly in the water. Additional fertilization is also unnecessary if pond water is used for watering.

If rain or tap water is poured, however, this washes the nutrients out of the soil over time. These should be replaced at least once every one to two years. Plant manure, for example from nettles or grass clippings, as well as compost are suitable for this. The plant manure can be used instead of the irrigation water, the compost is to be lifted under the substrate.

To cut

Whether in water or on dry ground – it should be an annual blending. Spring before the first shoot is ideal for this.

The purple loosestrife can also be cut in autumn, but this would eliminate a source of food for birds and a very simple form of reproduction.
In spring, all shoots that have dried out or withered are removed. There should be a good hand’s breadth left above the floor.

Stimulating the bloom on the purple loosestrife
The purple loosestrife blooms for a very long time anyway, but the splendor can even be extended with a simple measure. All that is necessary is to cut off the faded ears and buds. In this way, the plant is stimulated to sprout again and to produce more flowers.


The purple loosestrife takes on the simplest form of propagation all by itself if the dried flowers are not cut off too early. As soon as they are fully ripe and dry, the seeds fall out of the ears by themselves and are dispersed by the wind and birds. You can expect young plants as early as the following spring. However, this form is unspecified and therefore only recommended in large gardens that are kept close to nature. If you want to work in a more controlled way, you collect the ears and win the seeds in this way.

Another option is dividing the roots. To do this, the plants are dug up, the roots divided in the middle and the young plants that have emerged are reinserted.


The purple loosestrife is a native plant that can withstand harsh winters without any problems. And that even without special protection.
Whether it is cut in spring or autumn, in water or on land – it does not become more susceptible. In very long and harsh winters, however, the Lythrum salicaria standing in the water can be damaged. If such a thing is foreseeable, they should be put in a bucket and thus in a frost-free room, for example in a cellar. Alternatively, they can also be planted outside the water before the first frost.

Typical diseases and pests

The Lythrum salicaria is robust against diseases and pests, but has two special features.

The plant is a real magnet for butterflies, bees and bumblebees, especially during the flowering period. It is inevitable that caterpillars will feast on it once in a while. However, there is no need for action here. Infestation and traces of eating are kept within narrow limits. Other pests are also only found on the purple loosestrife for a short time and only if they have lost their way. Not even the otherwise voracious snails and aphids settle on it. On the contrary, they are more likely to be put off by the essential oils in the plant.

Leaf spot disease can still become a problem. This is expressed by black and brown spots that can be found on the upper and lower sides of the leaves. If the infestation is very small and limited to only a few leaves, the diseased parts should be removed and destroyed. With appropriate fungicides it may then be possible to save the Lythrum salicaria.

If, on the other hand, the spots have already spread, the whole plant must be destroyed. Otherwise, other plants will also become infected.
In order to prevent the fungal disease from the outset or at least reduce the risk, it is essential to adapt the location or care. Leaf spots break out if the substrate is too moist, the air is too cold or if there is no ventilation. Basically only when the purple loosestrife is too narrow, is not adequately ventilated in a greenhouse or in a pond with poor water quality.

Is the purple loosestrife poisonous?

The purple loosestrife is a medicinal plant that can be used for a variety of diseases and injuries.

So it is by no means poisonous. It is therefore not a concern if children or pets come into direct contact with it while playing or if skin contact occurs when it is cut. It can also be used as food for small animals. Due to the essential oils and tannins, however, it is usually not very popular with them. For this reason, it is ideal for permanent and beautifying planting of open spaces, as it usually remains largely undamaged.

However, the Lythrum salicaria can pose a health problem.

Beware of allergies
The purple loosestrife has an attractive effect on flying insects, such as butterflies and bumblebees, but also bees and wasps, especially during the flowering period. Pests, on the other hand, stay away.

First and foremost, this is nice to look at and good for the garden, as beneficial insects are attracted, but parasites are deterred. Still, it can become a problem for allergy sufferers. Especially when the purple loosestrife is close to the house or in an open dining area. Because bees and wasps switch from flowers to juice or grilled food. So some caution is advised here.Conclusion
The purple loosestrife is a colorful display of flowers that is second to none and has a seductive effect on butterflies. The plant is easy to care for and undemanding, scares off pests and proves to be resistant to many influences. This makes them the ideal jewelry for gardeners and anyone who would rather relax in the garden than weed.

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