Petasites albus - White Butterbur, Bog Plant

Petasites albus, known as white butterbur, is a spreading perennial for wet, shady ground. In late winter and spring it produces white, honey-scented flowers before the leaves, followed by very large, heart- to kidney-shaped leaves that form a dense canopy.

White butterbur at a glance

Botanical name	Petasites albus
Common name	White butterbur
Plant type	Spreading perennial with creeping rhizomes; dies back in winter
Height and spread	Flowering clumps about 30–60 cm; spreads 1.5 m or more
Flowers	White, scented, before the leaves, February to May
Position	Part shade; sun only in constantly moist soil
Soil	Constantly moist to wet, humus-rich soil
Pond depth	None – wet soil on land, not under water
Hardiness	Hardy; naturalised in the UK since 1840 (not rated by the RHS)
Native to	Not UK native

Is white butterbur a pond plant?

No. It grows in wet soil and on shady riverbanks, not under water. Plant it in constantly moist ground, not in the pond.

Is white butterbur invasive?

Yes. The GB Non-Native Species Secretariat says it forms dense patches that crowd out native plants, and pieces of rhizome regrow and travel downstream along watercourses. The BSBI records it as invasive in parts of eastern and central Scotland, where it destabilises riverbanks. It is legal to buy and grow in a garden (in Scotland it is an offence to plant it in the wild), but plant it only where it can be contained, never near streams, rivers or wild land, and dispose of unwanted roots responsibly.

Is it poisonous?

Do not eat it. Butterburs (Petasites) as a group are known to contain pyrrolizidine alkaloids, which are linked to liver damage; no test of this species was found.

Which size should I buy?

Bare-root plants (7 cm, 9 cm, 1 litre and 3 litre) arrive without a pot or compost and are the most economical way to plant a group. Potted plants (9 cm, 1 litre and 3 litre) arrive growing in our peat-free compost and give a faster display. Packs of 3 come in 7 cm, 9 cm, 1 litre and 3 litre bare-root sizes and cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.