Viminaria spp.

native broom

HardinessZones 9–11

Overview

Viminaria spp. is a monotypic genus in the pea family containing the single Australian species V. juncea, a tall shrub or small tree reaching 2-6 m (6.5-20 ft). Mature plants are nearly leafless, the foliage reduced to scales, so photosynthesis is carried out by slender, drooping green branchlets that hang in a soft, weeping curtain and give the plant a rush-like appearance. Seedlings and young growth bear trifoliolate leaves that are shed as the plant matures. From spring into early summer, short pendulous racemes of yellow to orange-brown pea flowers, each about 1 cm (0.4 in) across, line the branchlets and are followed by small one-seeded pods. The species grows naturally in seasonally wet, sandy soils along swamp margins, creek banks, and winter-wet flats across much of southern Australia. Its roots fix nitrogen through symbiotic bacteria and tolerate periodic waterlogging, but the plant has little drought tolerance once established sites dry out. Growth is upright with weeping branch tips rather than spreading, and the green stems remain photosynthetic year-round. In gardens it is grown for the weeping habit and spring flowers in damp, sunny positions.

Native Range

V. juncea is endemic to Australia, where it grows in seasonally wet, sandy soils on swamp margins, creek banks, and winter-wet flats. Its range covers southern Western Australia, South Australia, Victoria, Tasmania, New South Wales, and southern Queensland. It is most common in coastal and near-coastal heath and woodland.

Suggested Uses

Grown in bog gardens, pond and dam margins, and damp low spots where its weeping habit and spring flowers suit informal native plantings. Also used for revegetation and erosion control on seasonally wet sandy sites. Tolerates coastal exposure in frost-free districts.

How to Identify

Mature plants are recognised by their leafless, weeping green branchlets that hang vertically and photosynthesize in place of leaves. Short racemes of small yellow to orange-brown pea flowers appear along these branchlets in spring. The combination of a tall, broom-like weeping habit, reduced foliage, and wetland habitat distinguishes V. juncea from true brooms and from rushes.

Appearance

Size & Dimensions

Height6'6" - 20'

Width/Spread3' - 10'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Spring

Flowering occurs in spring and early summer, roughly September to December in the native range. Pendulous clusters of small pea flowers open along the green branchlets over about six weeks. Small papery pods follow and ripen through summer.

Detailed Descriptions

Flower Description

yellow to orange-brown

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range4.5 - 6.5(Acidic)

357912

Soil Types

sand peat

Drainagewet

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2-3 years to flowering size

Care & Maintenance

Care Guide

Plants grow in full sun in moist to wet, sandy or peaty soils that are acidic to neutral, including sites that flood seasonally. Consistent moisture matters most, as the species comes from winter-wet flats and declines where soils dry out for long periods. Nitrogen-fixing root nodules let it grow in low-fertility sand without added feeding. Light frost is tolerated once established, but hard freezes damage the soft branchlets. Plants are short-lived, often declining after 10 to 15 years, and are renewed from seed. Root-rot fungi can attack plants in soils that are wet and warm rather than wet and cool.

Pruning

Light tip pruning after flowering keeps the weeping crown dense and removes spent flower clusters. Hard pruning into bare older wood is tolerated poorly. Plants are generally left to develop their natural weeping form with minimal cutting.