Growli
Let's go

Plant care

Persicaria amplexicaulis 'Alba' (white mountain fleece) care

Persicaria amplexicaulis 'Alba'

Also called white mountain fleece, white bistort.

RHS H7USDA 4-8Mildly toxic to petsIndoor 0.9-1.2 m tall and 0.9-1.2 m wide.

Watering rhythm

3-5days

Keep soil moist; water every 3-5 days in dry spells, especially in sun

Jump to schedule→Get smart reminders in the app

Light

Direct sun (at least 4-6 hours)

Soil

Moisture-retentive, fertile loam or clay

Humidity

40-70%

Temp

-20 to 28°C

Pet safety

Mildly toxic to pets

Mature size

0.9-1.2 m tall and 0.9-1.2 m wide.

Care at a glance

Light

Persicaria amplexicaulis 'Alba' needs sun on the leaves, not just bright ambient room light. Full sun to partial shade. Sun gives the densest flowering, but it performs well in dappled shade provided the soil stays reliably moist. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water persicaria amplexicaulis 'alba' keep soil moist; water every 3-5 days in dry spells, especially in sun. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Moisture-loving and intolerant of prolonged drought. Established clumps cope with brief dryness but flower best in consistently damp ground; mulch to retain moisture.

Soil and pot

Persicaria amplexicaulis 'Alba' grows best in moisture-retentive, fertile loam or clay. Thrives in heavy, damp soils where many perennials struggle. Any reasonably fertile, moisture-holding ground suits it; it tolerates clay readily. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Persicaria amplexicaulis 'Alba' sits happiest at around 40-70% humidity and -20 to 28°C (-4 to 82°F). An outdoor perennial unaffected by air humidity; normal garden conditions are ideal. It is not grown indoors. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed persicaria amplexicaulis 'alba' sparingly. Undemanding. A spring mulch of well-rotted compost or a single application of balanced general fertiliser sustains the season's growth; over-feeding is rarely necessary in fertile soil. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on persicaria amplexicaulis 'alba' in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Drought stress — Leaf scorch and early dieback follow dry soil in full sun; keep ground moist and mulched through summer.
  • Spreading vigour — Robust clumps expand steadily and can crowd smaller neighbours; lift and divide to keep them in bounds.
  • Flopping in shade — Stems grow lax and lean toward light in too much shade; site in good light for self-supporting growth.
  • Slug damage on new shoots — Emerging spring shoots are grazed by slugs and snails; protect young growth until established.

Propagation

Easiest by division in spring or autumn; sections of the spreading crown re-establish quickly in moist soil. Named selections are propagated by division to keep flower colour true. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Persicaria amplexicaulis 'Alba' is mildly toxic to pets. Persicaria (mountain fleece, bistort) is not individually listed by the ASPCA Toxic and Non-Toxic Plants database, so its status is unconfirmed; treat with caution and verify with a vet. Ingestion of foliage may cause mild gastrointestinal upset in cats and dogs. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Persicaria amplexicaulis 'Alba' care — frequently asked questions

What is the common name for Persicaria amplexicaulis 'Alba'?

Persicaria amplexicaulis 'Alba' is most commonly called Persicaria amplexicaulis 'Alba', but it is also known as white mountain fleece, white bistort. The names refer to the same species, so care instructions for Persicaria amplexicaulis 'Alba' apply identically to anything sold as white mountain fleece.

How much light does persicaria amplexicaulis 'alba' need?

Persicaria amplexicaulis 'Alba' grows best in direct sun (at least 4-6 hours). Full sun to partial shade. Sun gives the densest flowering, but it performs well in dappled shade provided the soil stays reliably moist.

How often should I water persicaria amplexicaulis 'alba'?

Water persicaria amplexicaulis 'alba' keep soil moist; water every 3-5 days in dry spells, especially in sun. Moisture-loving and intolerant of prolonged drought. Established clumps cope with brief dryness but flower best in consistently damp ground; mulch to retain moisture. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is persicaria amplexicaulis 'alba' toxic to cats and dogs?

Persicaria amplexicaulis 'Alba' is mildly toxic to pets. Persicaria (mountain fleece, bistort) is not individually listed by the ASPCA Toxic and Non-Toxic Plants database, so its status is unconfirmed; treat with caution and verify with a vet. Ingestion of foliage may cause mild gastrointestinal upset in cats and dogs.

What USDA hardiness zone does persicaria amplexicaulis 'alba' grow in?

Persicaria amplexicaulis 'Alba' is rated for USDA zone 4-8 and RHS hardiness H7. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Persicaria amplexicaulis 'Alba' deep-dive guides

Every aspect of persicaria amplexicaulis 'alba' care, each with its own calibrated guide:

Featured in these plant shortlists

Persicaria amplexicaulis 'Alba' qualifies for 5 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Persicaria amplexicaulis 'Alba' is also commonly called white mountain fleece or white bistort.