Bistort is the common name for plants of the genus Bistorta, some of which were formerly known as Persicaria and Polygonum. These are all hardy perennials, some evergreen and some deciduous, and include common bistort (Bistorta officinalis), which is native to the UK. Bistorts are attractive and easily grown plants which bloom from midsummer to early autumn, depending on the species. Bistort flowers are typically spikes made up of many tiny cup-shaped flowers, in colours that include pink, red, and white. In autumn, the leaves of some species develop colourful autumn tints. Bistort height varies considerably depending on the species and variety, from as short as 25cm up to 1.2m.

Advertisement

Common bistort is considered an herb by some as it's edible. In the North of England, it's known as pudding dock or passion dock as it was once used to make a traditional dish, around the time of Lent.

Note that contact with bistort may cause skin irritation.

How to grow bistort

Grow bistort in moisture-retentive soil in sun or partial shade, in a position that suits the height and spread of the variety. Keep watered until established, after which little care is required apart from cutting off faded flowers and dead growth. Propagate by division in spring or autumn.


Where to grow bistort

Bistorta 'Superba'. Torie Chugg
Bistorta 'Superba'. Torie Chugg

Grow bistort in borders, naturalistic and and woodland edge-type planting schemes. Because bistort forms large clumps, some people consider bistort to be a weed. However, as the definition of a weed is ‘a plant growing in the wrong place’, this is rather subjective.


How to plant bistort

Bistort growing as part of a mixed border. Paul Debois
Bistort growing as part of a mixed border. Paul Debois

Bistort is a tough and hardy perennial, so can be planted in autumn or spring, or in mild spells during winter. Plant into moisture-retentive soil or improve if needed by adding plenty of organic matter before planting.


How to care for bistort

Persicaria amplexicaulis 'Orange Field'. Jason Ingram
Persicaria amplexicaulis 'Orange Field'. Jason Ingram

If planting in spring, ensure plants are kept watered for their first growing season. Once established, bistort needs little care apart from trimming back dead flowers, and cutting back the dead foliage of herbaceous varieties before new growth emerges in spring.


How to propagate bistort

Divide established clumps of bistort in autumn or spring.


Pests and diseases of bistort

Bistort is usually a trouble-free perennial that is not subject to pests or diseases.

Advice on buying bistort

  • A range of bistort species and varieties are available in garden centres, nurseries, and online
  • Note that some suppliers still list bistort under its previous botanical name of Persicaria
  • Always check plants for signs of damage or disease before planting

Where to buy bistort online

Bistort varieties to grow

Persicaria amplexicaulis. Jason Ingram
Persicaria amplexicaulis. Jason Ingram

Bistorta officinalis is a handsome wildflower for woodland edges and meadow-style planting where soil is moisture-retentive. The variety 'Superba' is considered more garden-worthy than the species. Height x Spread: 90cm x 90cm

Bistorta affinis is a low-growing and spreading bistort, that makes excellent ground cover, particularly as it has evergreen foliage, with a choice of pink or red flowers. H x S: 90cm x 60cm

Bistorta amplexicaulis forms good-sized clumps of upright stems: the variety ‘Firetail’ is often called red bistort, due to its showy crimson-red flowers. H x S: 1.2m x 60cm


Frequently asked questions

Is bistort invasive?

Bistort is vigorous and easy to grow but is rarely invasive. Some species that make good ground cover plants are wide-spreading and should be given room to expand, though that is not the same as being invasive. The wildflower, common bistort, does grow vigorously in the damp places which it prefers.

What is the common name for bistort?

Bistort is the common name for the plant genus Bistorta.

Is bistort the same as Persicaria?

Advertisement

Yes. Most, but not all, of the species formerly known as Persicaria have been reclassified under Bistorta (bistort). So, for example, Persicaria affinis is now Bistorta affinis, and Persicaria amplexicaulis has become Bistorta amplexicaulis.

Advertisement
Advertisement
Advertisement