Quick Facts

Quick facts

• Originally from Europe, North Africa and Asia Minor, Crow Garlic (Allium vineale) is an erect, strong smelling perennial up to 1m high, reproducing by bulbils, bulbs and seeds.
• It can be distinguished by a strong garlic smell when crushed, small bulbs around the main bulb, cylindrical stems, hollow, almost cylindrical, leaves, and flowers mostly replaced by bulbils.
• It often occurs on poorly drained, heavy soils of pastures and river banks.
• It is an important weed of pastures, cereal crops and vineyards, causing problems in most temperate regions of the world.
• Although mostly a weed of agriculture, it is also known from roadsides and native vegetation
• Control involves a combination of tillage, grazing, and use of chemicals over a number of years.

What Does It Look Like?

What is it?

Crow Garlic (Allium vineale) is an erect, single stemmed, strong garlic smelling, perennial bulbous herb, growing 300 mm up to 1.2 m high, with 2–4 long leaves, and single dense round flowering head called an umbel. Crow Garlic mainly reproduces by vegetative means, producing up to 300 sessile (stalk-less) bulbils (above ground small bulbs produced on the flowering head, or in other plants sometimes produced and formed in the axil of a leaf) each bulbil potentially growing in to a new plant. Vegetative reproduction also occurs less commonly via bulblets (underground small bulbs arising from another bulbs). Crow Garlic can also produce seeds when flowers are produced. 

Stems are erect, hollow, and cylindrical 3–12 mm diameter. The 2–4 leaves are 150 – 600 mm long, and 1.5–4 mm wide, hollow and cylindrical at first, then grooved on the upper surface. Roots are shallow and fibrous. Up to 6 bulblets are formed below ground in the axils of the leaves around the old bulb at the base of the plant. The central one (5–10 mm diameter) has a soft white shell while the others (5–15 mm diameter) around it have hard brown shells.

Flowers are green and white to pink, 2–4.5 mm long, on pedicels (flowering stalks) 5–30 mm long , flowers are 2–4.5 mm mm long but are seldom seen, produced in terminal heads (umbels). Most [flowering] heads rarely produce flowers, normally only producing sessile bulbils. Bulbils are 5–7 mm long, obovoid, (egg-shaped, with wider portion at tip or apax), brown, smooth and shiny. Up to 300 bulbils are produced in a terminal umbel (head) to 30 mm diameter. As bulbils mature, they sometimes have long twisted leaf-like fresh green bracts growing between them, vastly exceeding them.

Seeds are produced in capsules about. 3–3.5 mm long, seeds are black and 3-4 mm long. (Parsons & Cuthbertson 2001; VicFlora 2016).

For further information and assistance with identification of Crow Garlic, contact the herbarium in your state or territory.

Flower colour

White, Pink, Green

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Crow Garlic often occurs on poorly drained, heavy soils of pastures and riverbanks (Parsons & Cuthbertson 2001).

Are there similar species?

There is no record of Crow Garlic being commonly mistaken for other species. It can be distinguished by a strong garlic smell when crushed, small bulbs around the main bulb, cylindrical stems, hollow, almost cylindrical, leaves and flowers mostly replaced by bulbils.

Why Is It A Weed?

What are its impacts?

Crow Garlic has an offensive garlic-like odour due to allyl sulphides. It is mostly a weed of agriculture, but also invades or is present in some native vegetation types, seen on roadsides, and occurs in urban areas.

Agriculture: Crow Garlic gives a strong garlic odour and flavour to agricultural produce, particularly cereal grain, grain products, milk and meat. The garlic flavour appears in milk after only a few minutes grazing and it takes about 6 hours of feeding on non-infested pasture before the taint is lost (Parsons & Cuthbertson 2001). The bulbils are difficult to remove from grain after harvest and contaminated grain is rejected at grain silos, but may be sold as stockfeed at a reduced price. The plant has the potential to have a significant impact on quality of produce due to contamination (Government of South Australia 2015). Classed as a contaminant by the Australian Wheat Board and contaminated wheat will be rejected at the silo. Similarly, contaminated barley is unacceptable for malting. Rejected grain might be sold as stockfeed but should not be fed to animals producing milk or meat. An additional problem is that infested grain milled for stockfeed often clogs the mills rollers (Parsons & Cuthbertson 2001). Species of Allium rarely cause stock illness but Crow Garlic is suspected to have caused cattle poisoning in Britain. Cattle appear to be more susceptible than sheep to Allium poisoning. The toxic principles in Allium species cause anemia, disturbances in fat metabolism and enzyme activity in the liver. Problems are unlikely to arise if animals are offered a mixed diet.

Native ecosystems:  Crow garlic (Allium vineale) is regarded as an environmental weed in South Australia, New South Wales, Tasmania and Victoria. although Crow Garlic it is also spreading and becoming troublesome in natural habitats, this species is mainly seen as a pest of agriculture, (Queensland Government 2016) as recognised by Government of South Australia (2015). Crow garlic is also an invader of native vegetation, and is recorded  to occur in native vegetation (AVH 2021).

Urban areas: A weed of roadsides and waste land. There have been cases of poisoning caused by the consumption of field garlic, in large quantities and by some mammals. Dogs seem to be particularly susceptible (Government of South Australia 2015).

How does it spread?

The bulbs, bulbils and seeds of Crow Garlic can be spread by the movement of contaminated hay, grain, machinery, animals and water. The transporting and planting of contaminated wheat has greatly contributed to the wide distribution of Crow Garlic. The bulbils are similar in size and shape to wheat grains and are difficult to remove in cleaning operations (Parsons & Cuthbertson 2001; Fisher 2007).

What is its history in Australia?

The history of Crow Garlic in Australia is not fully known, but it is suspected that it was introduced in the late 19th century as a grain contaminant (Government of South Australia 2015). In Australia Crow Garlic was first recorded as wild in South Australia in 1910 (AVH 2021). However, Crow Garlic was listed in a catalogue of plants being grown in the Melbourne Botanic Gardens in 1853, where it may have been introduced as a culinary plant (Parsons & Cuthbertson 2001).

How To Manage It?

Best practice management

Variations in dormancy and germination times of bulbs, bulbils and seeds of Crow Garlic make it well adapted for survival and difficult to control. A management program integrating grazing, cultivation and chemical control extending over at least five years may be required to eradicate this weed. A priority should be to prevent formation of aerial bulbils and seed to avoid further spread of infestations.

Chemical control: Crow Garlic can be killed by a number of herbicides but, as with cultivation, treatments must be repeated for several years to ensure all bulbs have germinated (Parsons & Cuthbertson 2001). A number of cheap herbicides routinely used in cereal cropping are effective against Crow Garlic in South Australia. It has disappeared from some areas since the introduction of sulfonylurea herbicides in the 1980s (Government of South Australia 2015).  A selection of herbicides are listed in Parsons & Cuthbertson (2001) and, Invasive Species Unit, Biosecurity SA (2018).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au 

Non-chemical control: Physical control: Removing individual or small plant id possible. However, all bulbs and bulbets should be removed and plants should be removed before bulbils drop from the flowering / bulbil heads.

Mechanical control: Cultivation can kill the majority of plants but needs to be repeated for several years to effectively eradicate the population. Cultivation is best used in conjunction with chemical treatments. 

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

The bulbs, bulbils and seeds of Crow Garlic sprout after the first autumn rains. During winter and spring the leaves and stems develop while underground bulbs form at the base of the plant. Some hard-shelled bulbs may remain dormant for up to 6 years. Plants arising from seeds of bulbils produce bulbs in early spring but do not flower in their first year. Heads are produced in late spring through to summer. Most heads produce bulbils only, but some heads produce both bulbils and flowers. Some seeds are formed by the flowers but reproduction by seeds is minor. When the aerial parts of the plant die in late summer the bulbils are shed on to the ground (Parsons & Cuthbertson 2001)

Where Is It Found?

Which states and territories is it found?

NSW, SA, TAS, VIC, WA

What areas within states and territories is it found?

Crow Garlic occurs in all states of Australia except Queensland, and has not been recorded in the Northern Territory or the Australian Capital Territory.

Victoria is the worst affected, especially in the north central region in cereal crops and pastures. Crow garlic (Allium vineale) also appears on some local and regional environmental weed lists in Victoria (e.g. in the City of Mitcham, Brimbank City and the Goulburn Broken Catchment).and is  also reported to be having some localised impacts on remnant natural vegetation and rare native plants in Victoria. It has been recorded in Central Creek Grassland, a reserve of state significance that contains a piece of remnant Western Basalt Plains Grassland. In particular, it is seen as a threat to small populations of rye beetle grass (Tripogon loliiformis) in this reserve. This native species is rare in Victoria and inhabits a specialised niche in the grassland on the shallow mossy verges of exposed boulders. Crow garlic (Allium vineale) and other weed species are thought to be altering the structure of this niche, by increasing organic mulching and accelerating soil deposition among the moss mats Queensland Government (2016).

In South Australia, it is listed as a common environmental weed in the Adelaide region and as an invasive plant in bushland in the Adelaide Hills Council district and in coastal areas, and previously in the mid-north but has It has disappeared from some areas since the introduction of sulfonylurea herbicides in the 1980s (Government of South Australia 2015).

In Tasmania it is also a weed of pasture. It is little known in New South Wales, and there are a few records of its occurrence in Western Australia (Western Australian Herbarium 1998-; Parsons & Cuthbertson 2001; PlantNET (2021).

Where does it originate?

Crow Garlic is native to Europe, North Africa and Asia Minor and probably originated in the Balkans. It is an important weed of pastures, cereal crops and vineyards, causing problems in most temperate regions of the world (Parsons & Cuthbertson 2001; Fisher 2007).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NSW, SA, TAS, VIC, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Allium vineale

Other scientific names (synonyms)?

Allium vineale var. compactum (Thuill.) Lej. & Courtois (misapplied by Willis, J.H. 1962, A Handbook to Plants in Victoria. 1: 325.)

Does it have other known common name(s)?

False Garlic, Field Garlic, Stag's Garlic, Wild Garlic, Wild Onion