- Botanical name: Persicaria alpina
- Common name: Knotweed
- Family: Polygonaceae
- Plant Type: Perennial, Semi-evergreen
White
Green
- Key features:
- Attractive seedheads
- Flowers
- Low maintenance plant
Alpine knotweed, Persicaria alpina, is a substantial herbaceous perennial with pointed green leaves topped by fluffy flower plumes from midsummer and into autumn. Don’t be put off by its common name; Persicaria alpina is easy to grow, but not thuggish or invasive, although it does resemble Japanese knotweed.
Persicaria alpina enjoys growing in moist soil, so it’s a great choice for growing near ponds, allowing the water to catch its reflection.
For best results, grow Persicaria alpina in full sun or partial shade in moist, well-drained soil, sheltered from strong winds. Cut back the foliage to the base of the plant after it has been hit by the first frosts.
How to grow Persicaria alpina
-
Plant size
1.8m height
1.5m spread
-
Aspect
North facing, south facing, east facing, west facing
-
Position in border
Middle
- Sun exposure: Full sun, partial shade
- Hardiness: Hardy
- Soil type: Acidic / chalky / alkaline / clay / heavy / moist
Plant calendar
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow | ||||||||||||
| Sow |
J
Do not Sow in January |
F
Do not Sow in February |
M
Do Sow in March |
A
Do Sow in April |
M
Do Sow in May |
J
Do not Sow in June |
J
Do not Sow in July |
A
Do not Sow in August |
S
Do not Sow in September |
O
Do not Sow in October |
N
Do not Sow in November |
D
Do not Sow in December |
| Plant | ||||||||||||
| Plant |
J
Do not Plant in January |
F
Do not Plant in February |
M
Do Plant in March |
A
Do Plant in April |
M
Do Plant in May |
J
Do not Plant in June |
J
Do not Plant in July |
A
Do not Plant in August |
S
Do not Plant in September |
O
Do not Plant in October |
N
Do not Plant in November |
D
Do not Plant in December |
| Flowers | ||||||||||||
| Flowers |
J
Plant does not flower in January |
F
Plant does not flower in February |
M
Plant does not flower in March |
A
Plant does not flower in April |
M
Plant does not flower in May |
J
Plant does flower in June |
J
Plant does flower in July |
A
Plant does flower in August |
S
Plant does not flower in September |
O
Plant does not flower in October |
N
Plant does not flower in November |
D
Plant does not flower in December |
| Divide | ||||||||||||
| Divide |
J
Do not Divide in January |
F
Do not Divide in February |
M
Do Divide in March |
A
Do Divide in April |
M
Do Divide in May |
J
Do not Divide in June |
J
Do not Divide in July |
A
Do not Divide in August |
S
Do Divide in September |
O
Do Divide in October |
N
Do Divide in November |
D
Do not Divide in December |
| Cut back | ||||||||||||
| Cut back |
J
Do not Cut back in January |
F
Do not Cut back in February |
M
Do not Cut back in March |
A
Do not Cut back in April |
M
Do not Cut back in May |
J
Do not Cut back in June |
J
Do not Cut back in July |
A
Do not Cut back in August |
S
Do not Cut back in September |
O
Do Cut back in October |
N
Do Cut back in November |
D
Do not Cut back in December |
Persicaria alpina and wildlife
Persicaria alpina has no particular known value to wildlife in the UK.
Is Persicaria alpina poisonous?
Persicaria alpina has no toxic effects reported.
No reported toxicity to Birds
No reported toxicity to Cats
No reported toxicity to Dogs
No reported toxicity to Horses
No reported toxicity to Livestock
No reported toxicity to People
Plants that go well with Persicaria alpina
