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mountain rush

Juncus arcticus · Juncaceae

mountain rush (Juncus arcticus)
Photo: (c) Senna Bryce Robeson, some rights reserved (CC BY) · CC BY · via iNaturalist

mountain rush (Juncus arcticus) is a perennial grass or grass-like plant in the Juncaceae family. It is native to North America. USDA records it as hardy in zone 2 and warmer, down to about -43°F.

At a glance

Typegraminoid USDA
Lifecycleperennial USDA
Native statusnative USDA
Mature height4 ft USDA
Lightpart-shade USDA
Water needhigh USDA
Growth raterapid USDA
Soil pH6–9 USDA
BloomJune USDA
Flower colorBrown USDA
Hardiness zones2 and warmer USDA
Guild layerherb-layer Derived
Nursery availabilityRoutinely Available USDA

USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.

Growing conditions

It grows in partial shade. USDA rates it as having needs consistently moist ground. Its drought tolerance is rated low. It tolerates saturated, poorly drained ground well (USDA rates its anaerobic tolerance high). It is recorded on soils from pH 6 to 9 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 2.

Size and growth

At maturity it reaches about 4 ft, making it roughly waist to chest height. It grows quickly.

Bloom period

USDA records a bloom period of June. Flowers are brown.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is green, fine in texture. Its flowers are not conspicuous — a plant for form and foliage. Its active growth period is spring and summer. USDA rates its lifespan as long.

What the site needs to provide

It needs at least 90 frost-free days to finish its season. It roots to at least 20 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

Propagating it

Propagate it from seed and sprigs. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It spreads vegetatively at a rapid rate.

Resilience and wildlife

Browsing animals find it moderately palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated high. Its growth form is recorded as rhizomatous.

Role in a guild

Herb layer. In a layered planting this is the herbaceous middle — perennials and grasses that fill the space between ground cover and shrubs. The layer is derived by a fixed rule from growth habit and mature height.

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Tags

deciduoussalt-tolerantwet-tolerantclay-tolerantspreadingnativefast-growing

Related plants

Others in Juncus

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol JUARL, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.

Read our full data sources and methodology.

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