Herbaceous perennial · Subshrub
Persicaria filiformis
Tovara knotweed
Also known as: Persicaria tovara (invalid garden name), Antenoron filiforme, Persicaria virginiana ‘Filiformis’, Persicaria virginiana var. filiformis, Polygonum filiforme
An airy perennial with red-marked green leaves and slender coral-red flower spikes from summer into autumn.
- Full sun, Partial shade
- 0.8–1.4 m (3–5 ft)
- 0.5–1 m (2–3 ft)
- H6 · Zone 5
- July–October
- Deciduous
Overview
This clump-forming knotweed is valued for its dark leaf chevrons and wiry red flower spikes. The supplied name Persicaria tovara is not accepted botanically; Persicaria filiformis is used here.
At a Glance
Growing Conditions
Aspect Suitability
- North-facing
- East-facing
- South-facing
- West-facing
Site Tolerance
- Exposed sites
Soil Tolerance
- Clay
- Chalk
- Sandy
- Loam
- Acid
- Neutral pH
- Alkaline
Foliage
- Autumn colour
- Architectural foliage
Foliage interest: April–November
Seasonal Timeline
- Flowering Jul Aug Sep Oct
- Foliage Apr May Jun Jul Aug Sep Oct Nov
- Propagate Mar Apr Sep Oct
Maintenance Calendar
- Mar Cut old stems to ground level before new growth
- Apr Divide congested clumps if required
- Jul Water in prolonged dry periods
- Sep Remove flower spikes before seed ripens if spread is unwanted
Garden Design
Works well in: Contemporary, Cottage, Tropical, Tropical / Exotic, Underplanting, Wildlife, Woodland
The wiry flower spikes are most visible against plain green foliage or pale walls.
Companion planting: Ferns, Hostas, Acteas, Ornamental grasses
Wildlife Value
- Bees
- Other pollinators
- Beneficial insects
- Shelter