Soft rush
Juncus effusus
also called common rush
A fountain of smooth dark-green needle stems for the pond edge or rain garden, evergreen into winter, with little brown flower sprays bursting from the stem sides like sparks.
- Type
- Grass · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun to part shade
- Watering
- High; wet feet year-round suit it perfectly
- Soil
- Wet; pond margins, ditches and standing water to 10 cm
- Feeding
- Gentle all-organic
- USDA zones
- 4a–9b
- Frost tolerant
- Yes
- Plant out
- at the last spring frost
- Plant spacing
- 17.7 in
- In-row spacing
- 15.7 in
- Between rows
- 23.6 in
- Square-foot density
- Not suited to SFG
- Root system
- Rooted in the mud, under water
- Working depth
- 6–18 in
- Can reach
- 24 in down where the soil allows
- Spread
- 24 in–4 ft across, about 1–2× the width of the plant
- Shallowest pot
- 8 in of soil
It roots into the silt and gets its air down from the leaves, so it drowns in nothing and dies in an afternoon out of water. Plant it in a mesh basket of heavy loam, topped with gravel, and set the basket at the depth the leaves want.
The habit is Soft rush’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- When
- Not harvested. Comb or cut the clump in early spring, and deadhead in a small pond.
- What to look for
- Winter-browned stems among the green in March; seed sprays going brown in late summer.
- How to harvest
- Rake dead stems out with gloved fingers or shear the whole fountain to 15 cm in early spring. Snip the flower sprays before seed drops if volunteers in every wet crack would be unwelcome.
- How often
- One spring groom; one late-summer deadhead where it matters.
- Storing the crop
- Nothing to store, unless you fancy the old craft: the peeled pith of these stems, dried and dipped in fat, was the rush light that lit cottages for centuries.
- Generally trouble-free No notable pest or disease problems when grown in the right conditions — one of the easy ones.
The rush of rush lights and rush mats: the pith of these stems, peeled and dipped in fat, lit cottages for centuries. Rushes are round and sedges have edges, which is how to tell your pond plants apart with your eyes shut.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com