Acorus gramineus 'Ogon' - Golden Sweet Flag, Pond Marginal Plant

Acorus gramineus 'Ogon', known as golden sweet flag, forms low, arching fans of narrow golden-yellow leaves striped with green. It is semi-evergreen, so it keeps much of its colour through winter.

Golden sweet flag at a glance

Botanical name	Acorus gramineus 'Ogon'
Common name	Golden sweet flag, slender sweet flag
Plant type	Low, clump-forming, semi-evergreen perennial
Height and spread	Up to 30 cm tall, up to 50 cm wide
Flowers	Tiny and insignificant; grown for its leaves
Position	Full sun
Soil	Wet or very moist fertile soil
Pond depth	0–5 cm of water over the crown
Hardiness	RHS H6 – hardy in a very cold winter (-20 to -15°C)
Native to	East Asia (not UK native)

Where to plant golden sweet flag

The very edge of a pond, with no more than 5 cm of water over the crown
Bog gardens and permanently moist borders

How to plant and care for it

Plant in spring or summer in wet soil or very shallow water. Tidy old, brown leaves in early spring and divide every few years to stop clumps becoming congested. The RHS notes it can be short-lived in water that stays above 22°C for long periods.

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.