Crow Garlic

(Allium vineale)

What is crow garlic?

Crow garlic is a weed of crops and pasture. It is also known as field or wild garlic.
Crow garlic is a declared weed under the Tasmanian Biosecurity Act 2019 and associated Regulations. The importation, sale and distribution of crow garlic are prohibited in Tasmania.

How to identify crow garlic

Crow garlic occurs in two forms: vegetative plants which produce leaves only, and plants which produce leaves and a stem bearing the flower head.
Vegetative plants produce two or three long, slender, hollow, blue-green leaves. By maturity one soft central bulb and one or two hard offset bulbs are formed at the base of the plant.
Flowering plants are larger and produce four or five leaves and a single stem up to 1 metre in height. The flowering head is initially enclosed in a papery membrane, which in summer bursts open to reveal the flower or bulbils.
Flowering heads may produce flowers, bulbils, or a mixture of the two: in Tasmania flowers are rarely produced. Flowering plants produce a single, soft white offset bulb, and about six hard straw-coloured offset bulbs.
Each type of bulb and the bulbils can develop into a new flowering plant during the next season, although the hard offset bulbs can remain dormant for up to six years. Most of the plants growing from hard offset bulbs and from bulbils are vegetative. Flowering plants develop from central bulbs and soft offset bulbs.
For further help in identifying crow garlic, search the Dennis Morris Weeds and Endemic Flora database for crow garlic illustrations. If you are still in doubt about the weed you are dealing with, contact Biosecurity Tasmania on 03 6165 3777 for help.

Image top: crow garlic, © Zoya Akulova.
Images above: crow garlic, © CDFA.

Crow garlic in Tasmania

Crow garlic occurs in a number of agricultural areas throughout Tasmania.
Crow garlic can be a serious competitor of crops and pasture. Crow garlic can also taint the milk and meat of animals grazing on infested pastures.
In cereal crops the ripe bulbils are harvested with the grain and cannot be subsequently removed, making the crop unsaleable for malting or flour-milling.

What is the legal status of crow garlic in your area?

The legal responsibilities of landholders and other stakeholders in dealing with crow garlic are laid out in the Statutory Weed Management Plan for Crow Garlic

Use Table 1 (Zone A municipalities) in the Statutory Weed Management Plan for Crow Garlic to find out whether your area falls in an eradication or containment zone.

Detailed management and control guidelines for crow garlic can be found in the Crow Garlic Control Guide. Refer also to Herbicides for Crow Garlic Control. For further information see Weed Links and Resources.

Crow Garlic Control Guide

Do

Plan your control program, this will save time and money in the long-run;
Consider the impact of your control methods on off-target species, especially if herbicides are used;
Ensure machinery and equipment is washed down between sites or prior to contractors leaving site;
Carefully time your use of herbicide for best results (see Herbicides for Crow Garlic Control for more information);
Coordinate your control program with neighbouring landholders where your weed problem crosses property boundaries;
Revisit and regularly inspect the site and ensure follow-up is undertaken;
Use a combination of different control methods.

Don't

Don't introduce crow garlic to crow garlic-free areas (e.g. by failing to wash down machinery and equipment between sites);
Don't start your control program without first planning your approach;
Don't rely on one attempt at removal - follow-up is essential;
Don't rely on just one control method.

Spread of crow garlic

Established infestations increase largely due to germination of the central bulbs and offset bulbs.
Spread to new areas can occur through bulbs, offsets and bulbils being scattered by cultivation, movement of topsoil, and in mud on agricultural implements or on the feet of stock.
Bulbils can be dispersed by heavy rains, in hay, and more rarely, as an impurity in seed grains or pulse.

Avoid the introduction of crow garlic

If you are cultivating an infested paddock, always work from the clean end of a paddock into the infested area.
Machinery should be carefully washed down before leaving the infested area.
See the Washdown Guidelines for Weed and Disease Control for detailed information on how to wash-down equipment and personnel to reduce the chance of spreading crow garlic.

Cultivation

Avoid autumn-sown cereal cropping. The bulbs, bulbils and offset bulbs are scattered by autumn cultivation and the life cycle of the garlic coincides with that of the crop.
A program of spring sown cereal cropping can control a crow garlic infestation.
Where possible, cultivations should extend from autumn through winter into spring: the earlier cultivations stimulate germination, and the later cultivations damage the plants when their reserves of nutrient are exhausted.
Later cultivations may be replaced with the application of an effective herbicide.
Ensure the best growing conditions for the crop or pasture to maximise competition.

Chemical control

A number of herbicides are registered for use on crow garlic in Tasmania. See Herbicides for Crow Garlic Control for more information.

Herbicides for Crow Garlic Control

Important Disclaimer

To the extent permitted by law, the Department of Natural Resources and Environment Tasmania (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using information or material (in part or in whole) contained on this website.