Larry Hodgson published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This text was originally published in July 2013 in Gardens Central
Fleeceflowers are in the knotweed family (Polygonaceae), belonging specifically to the genera bistorta or persicaria (still listed as polygonum by some nurseries). The common name “fleeceflower” refers to the frothy bloom of some species while “persicaria” refers to the leaves resembling those of a peach tree (Primus persicaria). They all show their relationship to the true knotweeds (polygonum) by the swollen nodes (knots) on their stems.
The genus persicaria contains about 35 species of annuals and perennials, many very weedy, but the plants used ornamentally arc more spreaders than weeds. All very adaptable plants, they grow in full sun to moderate shade in just about any well-drained soil. Multiplication is by division or cuttings – they’re not always true to type from seed. Fleeceflowers are pretty much self maintaining as well. A bit of a spring cleanup is all they really need to perform year after year.
(Bistorta affinis, Persicaria affinis, Polygonum affine)
This superb groundcover is evergreen in my climate (Zone 4) under snow, but it may lose its leaves in winter in areas of Zones 3 and 4 where snow cover is lacking. It forms a mass of creeping stems covered with upright leather} leaves.
They’re dark green in summer and some turn rusty red in fall. At each stem tip there is a narrow bottlebrush of flowers. Their colour is almost impossible to describe as it changes constantly. The buds are light pink and the flowers are a paler pink. They then drop off, leaving darker pink calices that fill with rusty red seedpods. Since the plant reblooms all summer, yopu’ll find all four stages at once, and therefore a mix of colors, especially by season’s end.
The two common cultivars, ‘Darjeeling Red’ and ‘Superba’ (‘Dimity’), are much the same, so there’s no need to buy both. Calculate that the plant will attain 15-20cm (6-8”) in height. As for spread… well, as a groundcover, it will spread as far as you let it. Insert a barrier (a lawn border will do) into the garden to keep it from wandering too far. Zone 3.
(Bistorta amplexicaulis, Persiesria amplexicaulis, Polygonum amplexicaulis)
This is a tall one, producing upright narrow stems on creeping rhizomes. It produces rather large leaves that wrap around the stem at their base. The upper part of the stem branches into upright narrow spikes of red flowers (pink or white in some cultivars). The overall result is that of a big mound bearing colourful candles from late July through September or even October.
The species itself is quite invasive, but most modem cultivars have short rhizomes. Yes, they spread, but they can’t go very far. By planting other plants around it (which keep it from spreading), I can keep mine at about 1-1 5m (3.3-5′) wide. Do give it some space as it needs to be a certain width to create an impact. There are perhaps a dozen cultivars, most fairly compact, about 90-120cm (3-4’) high (the species reaches 1,5m or 5’). The bloom comes in shades of red, pink and white. ‘Golden Arrow’ has beautiful chartreuse leaves. Zone 4.
(Bistorta officinalis, Persicaria bistorta, Polygonum bistorta)
This is probably the species most seen in gardens. It is a classic plant of the English-style mixed border. It naturally forms short rhizomes, leading to a dense dome of large arching dark green leaves. Upright stems poke up through the leaves and bear upright bottlebrush spikes of pink flowers much larger than those of the previous species. They’re earlier as well – in June and July ‘Superba’ is the usual cultivar Though not truly invasive, it will spread over time if there is little competition It reaches about 1 m(3′) high by 75-100cm (2.5-3.5’) in width. Zone 3.
‘Red Dragon’ fleeceflower
(Persicaria microcephala, Polygonatum microcephalum)
This species is grown mainly for its foliage, its little late-summer balls of white flowers adding little to the show. The species itself, with pointed, heart-shaped leaves bearing a darker chevron (V-shaped marking), is rarely grown. Instead, everyone has eyes for the cultivar ‘Red Dragon.’ It bears purplish leaves with a silver-grey chevron with a deep purple centre. It likes moist soil, making it a good choice around water features. It’s only reliably hardy to about Zone 7, though it will do fine in Zone 6 with a good mulch covering. In late summer I take root cuttings and overwinter them on a windowsill so I can keep them from year to year.
This is the best behaved fleeceflower of the group… largely because it doesn’t survive the winter in most climates and therefore can’t spread. 60-120cm (24′) x 60-90cm (2-3’). Zone 7.
(Persicaria filiformis, Polygonum virginianum var. filiforme)
Japanese jumpseed is another species grown essentially for its attractive foliage, though its thin reddish stems and tiny red flowers that show up in late August through early October aren’t unattractive. Bearing large green leaves with a dark purple chevron in the centre, it is rarely grown. Instead, the cultivar’ Painter’s Palette,’ with irregular creamy variegation and a red and purple chevron, is the one usually seen. This pretty plant is better adapted to shade – even dry shade – than the other fleeceflowers described here. However, its hardiness is limited. Despite labels claiming it is hardy to Zone 4, I’ve had little success maintaining it in my yard. That’s because while the wild species, P.
virginiana, is quite hardy, and even native to Eastern Canada into Zone 4, this cultivar is derived from the less hardy Japanese subspecies, P. filiformis, which is not hardy below Zone 6. 60 x 60cm (2’ x 2’).
So there you go – a nice little genus of plants that could brighten up just about any garden.