Butomus umbellatus - Flowering Rush, Native Pond Marginal Plant

Butomus umbellatus, known as flowering rush, is a UK native marginal plant with narrow, grassy leaves that open bronze-purple and turn dark green. In summer, tall stems carry rounded heads of rose-pink flowers well above the leaves.

Flowering rush at a glance

Botanical name	Butomus umbellatus
Common name	Flowering rush
Plant type	Rush-like perennial; dies back in winter
Height and spread	Leaves about 60 cm; flower stems about 1 m (RHS: up to 1.5 m). Spread up to 50 cm
Flowers	Rose-pink, in rounded heads, June to August
Position	Full sun
Soil	Fertile mud or shallow water
Pond depth	5–25 cm of water over the crown
Hardiness	RHS H5 – hardy in a cold winter (-15 to -10°C)
Native to	UK and Ireland (native wild flower)

Where to plant flowering rush

Sunny pond shelves with 5–25 cm of water over the crown
The margins of wildlife ponds, lakes and slow streams
Formal ponds, where the upright leaves add height

Is flowering rush good for wildlife?

Yes. It is on the RHS Plants for Pollinators list and the flowers attract bees.

How to plant and care for it

Plant in an aquatic basket in spring or summer, in full sun. Cut back the old leaves in autumn. Watch for water lily aphid on the leaves in summer.

Is flowering rush invasive?

It is a UK native plant. It is invasive in North America, where it was introduced.

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 cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.