Persicaria polymorpha
Variable knotweed
Also known as Polygonum polymorpha
- Height × spread
- 2.5m × 2m
- Position
- Full sun
- Hardiness
- Colder than -20C (RHS H7)
- Flowers
- Summer
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This is a huge plant, it can positively overwhelm, and is certainly not suited to the dainty pocket handkerchief garden. However, its beautiful when placed in the right position. This is likely to be in a wild garden grown in grass, or at the back of a broad border. It makes a huge foliage clump of conical green leaves, up to 45cm in length, that arch outwards from the upright stalks. At the top, a froth of white, astilbe-like flowers appears. sometimes as early as May, more often in midsummer. The flowers, turn brown and pink, and then there are bronzed red fruits which continue to be a feature in August and even September. Once established it will have some drought tolerance.
- Flower colour
- White
- Foliage colour
- Green
- Variegated
- No
- Scent
- No
- Shape
- Cube
- Height
- 2.5m
- Spread
- 2m
- Season of interest
- Summer
- Flowers in
- Summer
- Evergreen
- Deciduous
- Garden style
- Wild flower meadow, Prairie garden
- Sun or shade
- Likes full sun, tolerates light shade
- Soil type
- Clay, Loam (normal)
- Soil pH
- All types
- Drainage
- Moisture retentive soil, Damp and wet soil
- Hardiness
- Colder than -20C (RHS H7)
- Borders & containers
- Borders
- Maintenance
- Easycare – low/no maintenance
- Hazards
- No
Spring
Spring - late · Outdoors
Feed with slow release fertiliser
Apply a general purpose slow release fertiliser, spreading it around the root area of the plant as it is coming into growth. (Or apply a liquid feed at regular intervals throughout the growing season.)
This is a simple way to provide a nutrient boost as a single annual procedure.
Spring-Autumn · Outdoors
Water to keep the soil moist
For best results, this plant needs soil that is always moist. Water deeply and regularly as soon as soil appears dry. Even for established plants in the ground, a dry week can cause problems with some soils. Check plants in pots more often, especially in hot weather. Or install an automatic irrigation system which will do the hard work for you, even when you are away on holiday.
Without regular watering some plants never fully regain their beauty.
Spring - early-mid · Planting
Divide when too large
The plant can be divided if it becomes too large or another plant is required. This may involve physically dividing the clump in two, removing offsets or small bulbs or dividing rhizomes. The new plants can be grown in pots or planted in the ground.
Found in
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