Persicaria amplexicaulis 'Speciosa' - Knotweed

The Persicaria amplexicaulis Speciosa is adorned from summer to autumn with numerous thick spikes of flowers, in a lovely shade of carmine pink in late summer and autumn. This perennial forms a vigorous clump, both tall and dense, with oval or heart-shaped green foliage that takes on beautiful colors in autumn. Easy to grow in any well-drained but moist soil, in full sun or partial shade in flower beds or near water sources.

The Persicaria amplexicaulis 'Speciosa' is a plant of the family Polygonaceae. It is a perennial that is more or less evergreen in winter, depending on the climate, and quickly forms a clump of 1 meter (3 feet) in all directions. This plant spreads more or less slowly, depending on the soil fertility, and can form imposing clumps. Very floriferous, this knotweed produces many spikes, 7 to 10 cm (3 to 4in) long and 2 to 3 cm (1in) wide, composed of small flowers that are carmine red in buds and become a little more pink when they bloom. The flowering is continuous throughout the summer, from July to September, if the soil does not dry out too much. The semi-evergreen leaves, carried by sturdy stems, are lanceolate to cordate in shape, measuring 15 to 25 cm (6 to 10in) long, and are embracing at the base. Their color is medium to dark green, they are villous on the underside and turn yellow-orange in autumn.

Very trendy, this knotweed with its highly decorative flowering fits perfectly in contemporary gardens as well as in wilder environments and forms superb autumn scenes with grasses. Thanks to its spreading habit, it can be used as a ground cover, making sure to leave enough space for it. This knotweed appreciates both sun and partial shade. It likes rich and heavy, moist or even very wet soils and can be cultivated independently on sunny pond banks and even in a fresh and partially shaded understory at the base of trees.