Lythrum salicaria or Purple Loosestrife is known by many other names, in fact, one of the longer lists of common names I have come across: Black Blood, Spiked Loosestrife, Purple Lythrum, Long Purples, Purple Grass, Rainbow Weed, Red Sally, Rose Loosestrife, Rosy Strip, Sage Willow, Soldiers, Spiked Loosestrife or Willow Weed. It is from the Lythraceae family of plants.
Lythrum salicaria is a herbaceous perennial. It naturally grows on banks of streams or around water. It is native to Europe, Asia, northwest Africa, and Southeastern Australia. It grows from 1m to 2m or 3 to 7ft. It grows into colonies and therefore has a strong impact on color in the landscape.
Lythrum salicaria flowers are reddish-purple and are clustered in bracts. It produces three different types of flowers with different length stamens and each flower type can only be pollinated by the other types. The flowers are pollinated by butterflies, bees, and other long-tongued insects. It flowers over a long period in the summer.
Lythrum salicaria is also used for medicinal purposes mostly as an astringent or treat diarrhea. But it is used as an ornamental flower in many gardens, especially in borders or wildlife gardens.
Grow Lythrum salicaria in the sun. It will probably do fine in any type of soil. It is used to poorly drained soil. You can propagate by division in spring. It is also self-seeding. You might want to deadhead the flowers after flowering to stop self-seeding. Watch out for slugs and snails. It is disease-free.
Also read about Lythrum virgatum ‘Dropmore Purple’