Soft rush
Juncus effusus · Juncaceae
A stiff, upright fan of smooth, round, dark green, leafless stems, with small tufts of brown flowers near the tips.
- Size
- 3 ft tall, 24 in wide
- Zones
- 4 to 9
- Light
- Full sun to part sun
- Flowers
- Grown for its leaves; flowers mid June to late July
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around soft rush
The planner designed this bed around soft rush when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, full sun. It chose the other plants from the 251 that suit those conditions and its wet soil, and says below why soft rush stands where it does.
The plants
- 1 Soft rush × 4, dark green leaves
- 2 Stemless gentian × 21, blue
- 3 Himalayan fleeceflower 'Darjeeling Red' × 5, pink
- 4 Garden phlox 'David' × 3, white
- 5 Inkberry 'Gem Box' × 1, dark green leaves
- 6 Columbine meadow rue × 3, lavender
- 7 Checkered lily × 12, purple
Why this plant
- Grown for leaf, not flower. So is inkberry 'Gem Box'. Leaf lasts all season, where a flower lasts a few weeks.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does inkberry 'Gem Box'.
Why here
- Anchors a back corner. At 3 ft it is one of the taller plants here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to garden phlox 'David' (3½ ft) and inkberry 'Gem Box' (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 4 plants in 2 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
Why now
- Here for its leaves, all year. They cover the 17 weeks between early March and late November when nothing on the plan is in flower.
- One of three evergreens. They are what the bed has to show from November to March.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 46% of the planted ground. The back corners are held by garden phlox 'David' and soft rush, the tallest plants on the plan. The bed is tied together by its repeats: two kinds come round again along it, stemless gentian and soft rush.
The planner's own design check: 10 Excellent, 6 Good, 1 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where soft rush goes in a border
At 3 ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
A strong vertical line for the edge of a pond or a rain garden, in water or out of it. It stays green all winter. It seeds in wet, open ground.
- Pond margins
- Rain gardens
- A vertical accent in wet soil
What to plant with soft rush
Plants recorded as good partners for it, and what each pairing does:
- Blue flag iris: adds the flowers, late May to late June; happy in the same wet soil.
- Marsh marigold: adds the flowers, mid April to early May; low enough (16 in) to stand in front of it; happy in the same wet soil.
- Cardinal flower: adds the flowers, late July to mid September; happy in the same wet soil.
Questions about soft rush
Does soft rush need sun or shade?
Soft rush grows in full sun (6 or more hours of direct sun a day) and part sun (4 to 6 hours of sun, including some afternoon sun).
It wants moist to wet soil, of average fertility, and plenty of water. It copes with soil that stays wet.
What zones does soft rush grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should soft rush be planted?
20 in (50 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many soft rush plants do I need?
At 20 in apart, set out in staggered rows:
- 4 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 14 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used four in two groups.
Is soft rush poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat soft rush?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
Will soft rush spread?
It seeds itself about; the risk of it taking over is moderate. Self-seeds in wet, bare soil. Cut off the seed heads beside ornamental ponds.
What does soft rush look like in winter?
Soft rush keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
More Juncus
- Blue rush 'Blue Arrows' Juncus inflexus 'Blue Arrows'
- Corkscrew rush Juncus effusus 'Spiralis'
In these guides
- Plants for wet soil and rain gardens
- Pet-safe plants for a sunny border
- Evergreen perennials, ferns and grasses
- Ornamental grasses under 3 feet
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Grass
- Size
- 3 ft (90 cm) tall, 24 in (60 cm) wide
- Plant
- 20 in (50 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- Mid June to late July; airy sprays; tan, green
- Leaves
- Fine texture, evergreen; dark green
- Shape
- Upright, self-seeding
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun, part sun
- Soil
- Average, moist to wet
- Water
- High
- Feeding
- None needed
- Family
- Juncaceae
- Comes from
- North America, W. South America, Eurasia
- Stands up to
- Wet soil
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.