About
Persicaria amplex. 'Blackfield' is a cultivar of Persicaria in the knotweed family Polygonaceae, notable for its summer flowering from July to September. It belongs to a genus of herbaceous plants that can be annual or perennial and shows a variety of stem and root habits. Flowers in Persicaria are carried in spikes, panicles or headlike clusters and may range in colour within the genus. The genus often bears a papery ochrea at the leaf nodes.
About the genus
Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds. It has a cosmopolitan distribution, with species occurring nearly worldwide.
Wikipedia contributors, "Persicaria", CC BY-SA 4.0 — Persicaria
In the garden
Persicaria amplex. 'Blackfield' sits within Persicaria, a cosmopolitan genus in the Polygonaceae (knotweed) family that includes both annual and perennial herbs. The genus displays diverse root systems — taproots, fibrous roots, and in many species rhizomes or stolons — and flowers in spikes, panicles or compact heads; flowering for this cultivar occurs from July to September. Garden handling should reflect those genus traits: expect herbaceous growth and allow room for lateral spread where rhizomes or stolons are present. The presence of a papery ochrea at the leaf nodes is a useful identification feature when checking plants in the nursery. After flowering, cut back or lift and divide clumps where spread is undesirable; removing spent flowerheads after September will keep plants tidy and reduce self-seeding. Use Persicaria amplex. 'Blackfield' where late-summer to early-autumn blooms are wanted; its flowering window bridges high summer into the autumn season and makes it a practical choice for extending interest through that period. Manage stands by annual trimming or occasional division so the cultivar retains vigour and a controlled footprint.
More in the Persicaria genus
- Persicaria amp. 'Blackfield'
- Persicaria amp. 'TaurusKnotweed
- Persicaria amplex. 'Alba'Knotweed
- Persicaria amplex. 'Taurus'Knotweed
- Persicaria rucinata 'Needham's Form'