Lysimachia (Loosestrife) is a useful plant for a damp site in partial shade. The genus Lysimachia includes about 150 species of herbaceous and evergreen perennials and shrubs, mainly growing in damp grassland and woodland or near water in subtropical regions.The erect stems bear white or yellow flowers, depending on which of the two species you grow, and you would never guess that they were related. Dig plenty of compost into the soil before planting and remember that these plants can spread rapidly.
To prevent them from crowding other plants, dig up the clumps, divide and then replant every three years. Creeping Jenny (L. nummularia) is an old favorite in rockeries. Creeping Jenny is a perennial plant with bright, small yellow flowers. Though the blooms won’t last long, they are pretty. For that reason, this low-growing “creeper” is best grown for its foliage, which makes an excellent ground cover.
Varieties of Loosestrife
Lysimachia clethroides (Chinese Loosestrife) bears curved spikes about 5 in. long of tiny white flowers — the lance-shaped leaves and flower spikes give it the appearance of a small Buddleia bush. Basic details are height 3 ft, spacing 2 ft, flowering period July—September. L. punctata (Yellow Loosestrife) is rather smaller (2½ ft) and blooms earlier (June—August). Its leafy stems bear whorls of yellow, starry flowers which have a reddish tinge at the base of the petals.
Any moisture-retentive garden soil will do — thrives in sun or partial shade.
Divide clumps in fall or spring. Lysimachia should be divided every 2 or 3 years.