Wild garlic [Allium vineale L.][ALLVI][CDFA list: B] Photographs Map of Distribution

Panicled onion [Allium paniculatum L. var. paniculatum][Bayer code: none][CDFA list: B] Photographs Map of Distribution

SYNONYMS:wild garlic: field garlic, scallions, wild onion, crow garlic

GENERAL DESCRIPTION:Noxious bulbous perennials with grass-like leaves.

• wild garlic: Plants have a strong onion or garlic odor when crushed, and when consumed by cattle impart a disagreeable flavor to their meat and milk products. Similarly, aerial bulbils can contaminate wheat. Introduced from Europe.
• panicled onion: Plants typically have a mild onion odor or lack an odor when crushed. Introduced from Southern Europe, probably as an ornamental.

SEEDLINGS:Leaves similar to mature leaves, but much smaller.

MATURE PLANT:Leaves basal, linear, glabrous, sheathing at the bases.

• wild garlic: Has 2 plant types: those that produce a scape (flowering stem) at the end of the growing season and those that do not. Plants that do not produce a scape are smaller and have fewer, more slender leaves. Plants that produce a scape typically have 2-4 leaves that appear circular and hollow in cross-section, are much longer than the scape, 15-60 cm long, 0.2-1 cm wide, and easily flattened when young.
• panicled onion: Leaves 3-5, narrowly channeled, less than or equal to the length of the scape, sheathing the lower 1/2 - 1/3 of the scape.

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ROOTS and UNDERGROUND STRUCTURES:Bulbs consist of a short, thick stem axis (basal plate) with a growing point surrounded by fleshy scale leaves. Short, firbrous roots develop from the bottom of the basal plate. Soft and hard-coated bulblets are produced in the axils of the scale leaves.

• wild garlic: Bulbs 1-2 cm long. Outer coat yellowish-brown, with longitudinally parallel fibers, splits into strips. Typically there are several hard-coated bulblets on stalks within the main bulb coats.
• panicled onion: Bulbs 1-1.5 cm long. Outer coat dark brown, with an obscure pattern. Inner coats light brown. Bulblets usually 1-3, about equal in size to the main bulb. Cut surface of a bulb quickly turns orange to dark red with exposure to air.

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FLOWERS:Umbels of flowers +/- spherical, with 1 or more papery bracts below. Petals separate.

• wild garlic: May-July. Scapes 30-100 cm tall, develop a few flowers and/or numerous grain-sized aerial bulbils. Bulbils smooth, shiny, ~ 5 mm diameter, often produce slender green leaves while still attached to the scape. Flower heads ~ 3 cm diameter. Flowers 3-4 mm long, greenish-white, pink, or reddish-purple, on stalks 1-1.5 cm long. Single bract short, deciduous, with a beak-like apex.
• panicled onion: Scapes 30-70 cm tall. Flower heads 3-7 cm diameter. Flowers 25-100, bell-shaped, 5-7 mm long, white to purplish-pink, on unequal stalks 1-4.5 cm long. Bracts 2, long-tapered, unequal. Longest bract 5-14 cm long, extends about 4-9 cm beyond the flowers.

FRUITS and SEEDS:Capsules +/- ovoid. Seeds dull black, minutely wrinkled.

• wild garlic: Seeds flattened, semi-circular, ~ 3 mm long.
• panicled onion: Seeds ovoid, ~ 4-6 mm long, 3-4 mm wide.

POSTSENESCENCE CHARACTERISTICS:Leaves die back in summer, but old scapes with capsules can persist into fall or winter.

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HABITAT:Disturbed sites, vineyards, orchards, cultivated areas. Plants thrive in areas that receive summer moisture.

• wild garlic: Also vegetable crops, turf. Grows best on heavy, fertile soils. Tolerates wet soils.
• panicled onion: Also nursery crops, landscaped areas.

DISTRIBUTION:Uncommon. San Francisco Bay region, lowlands of the southern North Coast Ranges, northern Central Coast.

• wild garlic: Also, central North Coast, southern Klamath Ranges, Sacramento Valley and adjacent lowlands of the northern Sierra Nevada foothills, To 100 m (330 ft).
• panicled onion: Also, lowlands of the northern South Coast Ranges. To about 50 m (165 ft).

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PROPAGATION/PHENOLOGY:Primary growth period is early spring to summer. Seed, bulblets, and bulbils disperse primarily through human activities associated with agriculture.

• wild garlic: Reproduces primarily by aerial bulbils and underground bulblets, rarely by seed. One plant can produce up to 300 aerial bulbils. Seeds, soft bulblets, and aerial bulbils are viable for about 1 year and typically germinate in fall with the first rains. Hard-coated bulblets can remain dormant for 1-5 years, and length of dormancy increases with depth of burial.
• panicled onion: Reproduces by seed and underground bulblets.The biology of this species is poorly documented.

MANAGEMENT FAVORING/DISCOURAGING SURVIVAL:Infestations are difficult to control because the bulbs are hard to eliminate. Repeated cultivation every 2-3 weeks from late fall through spring for several years can prevent seed and aerial bulbil or seed production and help deplete bulb energy reserves. Herbicide treatments just before flowering (bud break) combined with cultivation in late summer or fall can give good control, but may need to be repeated for several years. Cultivation is most effective under dry conditions.

SIMILAR SPECIES:There are numerous native Allium species in California, several of which are rare. However, native onions are typically not weedy. Only wild garlic develops aerial bulbils, and only panicled onion has an inflorescence bract that extends about 4-9 cm beyond the flowers. False garlic [Nothoscordum inodorum (Aiton) Nicholson] is a noxious weed that resembles panicled onion and lacks an onion or garlic odor when crushed. Unlike panicled onion, false garlic has petals that are fused at the base forming a short tube.

CONTROL METHODS: Prevention and control: These species generally impart an undesirable garlic or onion type flavor to contaminated food products including cereal grains, milk, meat, eggs, and poultry. These species reproduce by seed, underground bulblets, and aerial bulbils in the case of Allium vineale. Tillage may reduce seed production, but new plants rapidly emerge from underground bulbs. Repeated tillage may eventually reduce bulb reserves and result in plants with less vigor. At low densities, plants may be carefully removed by hand-pulling. Competitive crops that shade these species may also improve control. Effective herbicides include 2,4-D, triclopyr and dicamba.

References
Ferguson, G. P., G. E. Coats, G. B. Wilson and D. R. Shaw. 1992. Postemergence control of wild garlic (Allium vineale) in turfgrass. Weed Technology 6(1): 144-148.
Fitzsimmons, J. P. and L. C. Burrill. 1993. Wild Garlic (Allium vineale L.). Pacific Northwest Extension Bulletin 444. 2 pp.
Gast, R. E., R. A. Liebl, and F. W. Slife. 1990. Wild garlic (Allium vineale) control with thifensulfuron and DPX-L5300. Weed Technology 4(3): 592-597.
Leys, A. R. and F. W. Slife 1988. Absorption and translocation of carbon-14 chlorsulfuron and carbon-14 metsulfuron in wild garlic (Allium vineale). Weed Science 36(1): 1-4.
Leys, A. R. and F. W. Slife 1987. Comparison of chlorsulfuron and metsulfuron for control of Allium vineale L. Weed Research 27(1): 35-42.
Leys, A. and F. W. Slife 1986. The response of wild garlic (Allium vineale) to the timing of spray applications of chlorsulfuron. Weed Science 34(5): 718-723.
Khodayari, K., R. E. Frans, et al. 1985. Evaluation of chlorsulfuron in wheat (Triticum aestivum cultivar Forest) and in a wheat-soybean (Glycine max) double-cropping system. Weed Science 33(5): 746-749.
Peske, S. T. and A. H. Boyd 1985. Separation of wild garlic (Allium vineale) from wheat with a gravity table. Seed Science and Technology 13(1): 129-138.

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