Lysimachia clethroides - Loosestrife

Lysimachia clethroides is also called Chinese loosestrife because of its origins. It is also known as gooseneck loosestrife, a lovely name that celebrates the grace of its white, curved spike-shaped inflorescences. This botanical species blooms in the middle of summer, just above beautiful foliage that will turn orange and red in autumn. It is a hardy perennial with spreading rhizomes, which quickly spreads in moist soils, in full sun or partial shade. It is ideal for greening heavy and moist soils, or sunny banks. Make sure to leave space for this loosestrife as it can become invasive.

Chinese loosestrife belongs to the Primulaceae family. It is native to wet areas in Japan and China. This herbaceous perennial plant has a fine underground rhizome that is reddish and fibrous in texture, capable of spreading rapidly over long distances. With rapid growth, this species doubles in size within 2 years under good conditions. The plant develops a large clump of upright leafy stems, very regular in appearance, reaching 60 to 70cm (24 to 28in) above the ground from spring. The leaves are arranged opposite each other on the stems. They are lanceolate in shape and measure from 6 to 11cm (2 to 4in) in length. Their colour is a bright light green until late summer, then they turn red and orange in autumn, before dying off in winter. Flowering takes place from July to September, depending on the climate, and can last several weeks. Unique flower spikes appear at the tips of the leafy stems. They are composed of small, single white flowers measuring about 1cm (0.4in), tightly packed on a curved spike which is thick at the base and tapers towards the tip. In a large bed, these regularly spaced inflorescences, all facing the same direction, create an unusual pattern with a unique sculptural design. The above-ground vegetation of this deciduous plant dies in winter.

This vigorous loosestrife will be perfect for occupying wet areas, in full sun or partial shade. However, it is a formidable competitor for its neighbours: give it a large bed or the bank of a water feature. However, it is possible to limit its spread with a geotextile fabric or an anti-rhizome barrier, which will allow it to be planted with meadowsweet, rodgersias, lungworts, ornamental rhubarb, Siberian irises, botanical daylilies (tawny or citrine), veronicastrum, and stem-clasping knotweed, which are all vigorous plants that appreciate the same environments and will help create lush plantings in soils that remain moist in summer.