Persicaria bistorta is commonly called Bistort. This is a perennial with many positive features. Plants form a low mound of dense green foliage, bearing 4 to 5 inch upright spikes of bright-pink bottlebrush flowers through the summer months. It is excellent in the border, as well as for massed planting. It is especially well suited for a partially shaded waterside locations, but can be grown in full sun. If you remove faded flowers regularly you will encourage more buds and extend the bloom period.
Bistort is perfect for cutting and admirable in the border with Digitalis ‘Snow Thimble’. Clump-forming, it can easily be divided annually.
Bistorta is easily grown in average, medium, well-drained soils in partial shade. Best results are in moist, fertile soils that are not allowed to become completely dry. Consistent soil moisture is particularly important in hot summer climates such as the upper Midwest where this plant often does not perform as well as it does in cooler northern areas. It will certainly flower less in drier soils. Bistort spreads slowly by rhizomes, but is not considered too aggressive.
Bistort forms mounds that can reach a height of 24-30″. The leaves are large, 8″ long, lance-shaped, rumex-like, and dark green leaves with a white midrib that turns an attractive red in fall. Stems have sheathed joints. Dense, bottlebrush-like spikes (4-6″ long) of tiny pink flowers sit appear atop leafless stems rising well above the foliage in late spring to mid-summer. Repeat bloom may occur intermittently into fall. Plant was formerly known as and sometimes still listed for sale as Polygonum bistorta ‘Superbum’.
Use in partially shaded borders, cottage gardens, margins of streams, ponds, or water gardens.
No serious insect or disease problems.
Type: Herbaceous perennial
Hardiness Zones: 3 to 9
Height: 2 to 3 feet
Spread: 1.5 to 2 feet
Bloom Time: May to July
Bloom Description: Pink
Sun: Part shade
Flowers: Showy flowers
Leaves: Good fall color
Wildlife: Attracts birds, butterfly’s
Tolerates: Drought, deer, rabbits