Butterbur

How to recognise it

Habit

Robust perennial with thick, creeping rhizomes; forms dense stands about 1 m tall.

Leaf

Round to kidney-shaped with a heart-shaped base, 30–60 cm across or more, with a toothed edge and a grey-felted underside. Long, hollow, grooved leaf stalks rising straight from the ground.

Flower

In March–April, before the leaves: thick spikes of pinkish-lilac flower heads on a scaly stem 10–40 cm tall. Male and female flowers on separate plants.

Fruit/Seed

After flowering, the female flowering stems keep lengthening and carry seeds with white fluff.

Roots

Thick, fleshy rhizomes that spread far underground.

Confusion with

Colt’s-foot has yellow flowers and much smaller leaves. Greater burdock has oval leaves and, in summer, purple, hooked flower heads on a tall, branched stem. Giant butterbur, a garden plant, flowers greenish white.

Flowering: March–April

Why grow it?

• Very early nectar and pollen in March–April for bumblebee queens, honeybees and early solitary bees.
• The giant leaves give coolness and shelter to frogs, toads and other waterside animals.
• Its thick rhizomes bind the banks of streams and ponds.
• An impressive foliage plant for a large, wet garden or a pond edge.
• The leaves were once used to wrap butter, hence the English name butterbur.

Butterbur: where does it grow best?

• In the wild: banks of streams and rivers, wet tall-herb vegetation, wet woodland, ditches and damp verges.
• Partial shade to sun, as long as the soil stays wet; in dry sun the leaves wilt.
• Wet to moist, rich soil, preferably clay or loam.
• In the garden: only suitable for a large pond or stream bank, or a wet corner where it may spread.

Goes well with

• Marsh marigold: Yellow flowers in March–April, at the same time as the pink spikes.
• Meadowsweet: Creamy plumes in summer, on the same wet soil.
• Yellow iris: Upright, sword-shaped leaves as a contrast to the round giant leaves.
• Alder: The classic tree of stream banks, with butterbur at its feet.

Butterbur: when and how to plant it?

1. Buy a plant from a native-plant nursery, or ask for a piece of rhizome from someone whose patch has grown too big.
2. Plant in March or October in wet soil, at least 1 m from other plants.
3. Dig in a sturdy root barrier around the planting spot, or plant it where it may spread freely.
4. Set the piece of rhizome 5 cm deep and water generously.
5. Keep the soil wet throughout the first year.
6. Never dig up plants from the wild.

Care

Water

Keep wet. In a spot that is too dry, the leaves droop on warm afternoons.

Feeding

Not needed; by a stream or pond it finds enough food.

Spreading

Every spring, slice off runners outside the intended area with a sharp spade.

Leaves

Leave dead leaves in autumn as ground cover; they rot down quickly.

Neighbours

Little grows under the giant leaves. Plant neighbours well away.

Tip: Want the flowers without the takeover? Plant butterbur in a large, deep, bottomless container sunk into the pond edge.

Pruning and mowing

When: Not needed. You can leave the dead leaves in place in autumn.

How:

• In summer, feel free to cut away a few leaves if they shade a path or a neighbouring plant.
• Let the leaves die back and rot down in autumn.
• Cut off spent female flowering stems if you do not want seedlings.

Pruning calendar and basic rules

Propagation

Division

In March or October, cut off a piece of rhizome with a bud and plant it straight away. It takes easily.

Seed

Only if male and female plants grow nearby. Scatter fresh seed on wet soil in May.

Butterbur: how does it get through the winter?

Hardy to −30 °C.

• It dies back completely above ground; the thick rhizomes overwinter in the wet soil.
• In late February–March the flower buds appear as thick, pinkish-green clubs.
• Fully hardy, to about −30 °C.

Diseases and pests

• Spreading: The main reason not to grow it in a small garden. Use a root barrier or slice off the edges every year.
• Limp leaves: On warm days or in drought. Wetter soil or more shade helps; the leaves usually recover by evening.
• Slugs: Holes in the young leaves. The leaves are big enough; let hedgehogs, toads and ground beetles do their job.
• Shading neighbours: Low plants disappear under the leaves. Choose neighbours that flower early or are large themselves.

Through the year

• February: The first flower buds push through the soil.
• March: Flowering before the leaves; bumblebee queens on the flowers. Plant or divide.
• April: Last flowers. The first leaves appear.
• May: The leaves unfold. Slice off spreading rhizomes.
• June: Leaves fully grown. Water if the soil dries out.
• August: The leaves droop on hot days; keep the soil wet.
• October: The leaves die back. Plant or divide.
• November: Rest. Leave the leaves where they fall.

Did you know?

• Petasites comes from the Greek petasos, a broad-brimmed hat, after the giant leaves.
• In England butter was once wrapped in the cool leaves, hence the name butterbur.
• Male and female flowers grow on separate plants; after flowering, the female stems grow considerably longer to spread their fluffy seeds.