Salsola australis (Southern Russian Thistle)

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Salsola spp.

Russian thistles

Amaranthaceae

Eurasia, North Africa, and Australia

Deer Resistant Drought Tolerant

SunFull Sun

WaterVery Low · drought-tolerant

Overview

Salsola spp. is a genus of roughly 100 to 130 species of annual herbs and small subshrubs in the amaranth family, Amaranthaceae, distributed across Eurasia, North Africa, and Australia, with several species now naturalized across western North America. Plants form rounded, much-branched mounds 8 to 40 inches (20 to 100 cm) tall and wide, with stems often striped green, red, or purple. Leaves are alternate and narrow, 0.2 to 2 inches (5 to 50 mm) long; in many species they are cylindrical and somewhat fleshy when young and harden to a spine-tipped point as the plant matures. The flowers are small and lack petals, with five greenish to pink papery tepals set among stiff bracts, borne singly in the leaf axils through summer and autumn. After the seed ripens, the dried, rounded plants of species such as S. tragus break off at the stem base and roll in the wind, scattering seed as tumbleweeds. Salsola spp. grows in saline soils, deserts, roadsides, and cultivated fields, tolerating drought and salt that exclude most other plants. Several species are listed as noxious or invasive weeds in the United States and Australia, where windborne plants pile against fences and the dry stems carry fire. The young shoots of some species are grazed by livestock or cooked as a vegetable, and a few are sown to stabilize arid, saline ground.

Native Range

Salsola spp. is native to arid and saline regions of Eurasia, North Africa, and Australia. Several species, including the Russian thistle S. tragus, spread to the Americas, southern Africa, and elsewhere during the 19th and 20th centuries and are now naturalized on dry, disturbed ground.

Suggested Uses

A few Salsola spp. species are sown for soil stabilization and forage on arid, saline rangeland. Young plants are sometimes harvested as a cooked green. Most species are managed as weeds rather than grown by choice.

How to Identify

Recognize Salsola spp. by its rounded, densely branched form and narrow, often cylindrical leaves that end in a sharp spine on mature plants. Stems frequently carry red or purple stripes on a green ground. The tiny flowers sit in the leaf axils with papery, greenish to pink tepals flanked by stiff, spine-tipped bracts rather than showy petals. In autumn the tumbleweed species dry to a brittle, pale skeleton that detaches at the base and rolls before the wind.

Appearance

Size & Dimensions

Height8" - 3'4"

Width/Spread8" - 3'4"

Colors

Flower Colors

Foliage Colors

red

Fall Foliage Colors

Bloom Information

Bloom Period

~12 weeks

Summer Fall

Flowering runs from summer into autumn, roughly July to October across most of the range. The small, petalless flowers open in the leaf axils and are pollinated by wind. Seed ripens through autumn, after which the dried plants of tumbleweed species scatter it as they roll.

Detailed Descriptions

Flower Description

greenish to pink

Foliage Description

green, often tinged red or purple

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 Range6.5 - 8.5(Alkaline)

357912

Soil Types

sand loam clay

Drainagewell drained

Water & Climate

Water Needs

Very Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Salsola spp. species grow in full sun on dry, well-drained soils and tolerate salinity, heat, and long drought. They establish from seed on bare, disturbed ground and need no added water once germinated. Most species complete their life cycle in a single season, setting heavy seed before dying back in autumn. Several are regulated as noxious weeds, so cultivation is restricted in parts of North America and Australia. Where plants appear as volunteers, they are usually cut or pulled before seed set to limit spread. The young, fleshy shoots of some species are edible after cooking.

Pruning

Pruning is not part of growing Salsola spp., as the plants are annual and short-lived. Where they are managed as weeds, plants are cut or pulled before flowering to prevent seed dispersal. Removing them before the stems dry and detach reduces the spread of tumbleweed species.