HPIPM:Common chickweed

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Caryophyllanae
Order	Caryophyllales
Family	Caryophyllaceae
Subfamily	Alsinoideae
Tribe	Alsineae
Genus	Stellaria

Scientific Name

Stellaria pallida

Scientific Name Synonyms

Stellaria media var. glaberrima

Stellaria media ssp. pallida

Common Name

common chickweed

Common chickweed(Stellaria media)

Author: Cheryl A. Wilen, University of California Statewide IPM Program

Identification and Life Cycle

Common chickweed (Stellaria media) is a winter annual in the pink family (Caryophyllaceae). Common chickweed is a prostrate or erect, somewhat succulent annual that often forms a dense mat. In lawns, it rarely grows higher than 2 inches, but can be taller (4 to 6 inches) and less compact in gardens or under shaded conditions. The stems have a diagnostic band of hairs along one side and the bright green smooth leaves grow opposite each other on each node. The leaves have an obvious pointed tip. The flowers are small with five white petals. However, the petals are deeply divided so the flower appears to have 10 petals. The numerous seeds are borne in capsules at the end of the stalk. Roots are shallow and fibrous.

Habitats

Common chickweed will grow in a wide range of soils but does particularly well in neutral pH soils with high nitrogen. It tolerates low temperatures and can flower and fruit under snow cover. Common chickweed can be found in disturbed lands, cultivated fields, waste places, along the sides of trails and roads, in forests, and in gardens.

Impacts

Because of its ability to produce large numbers of seeds under cool temperatures, common chickweed rapidly colonizes any cool, moist area before winter or spring crops can become competitive. In commercial situations common chickweed can limit winter vegetable production by competing for space, light, and nitrogen. Additionally, common chickweed can serve as a host for insect pests such as lygus bugs and thrips as well as a reservoir host for tomato spotted wilt virus (TSWV) and cucumber mosaic virus (CMV).

Biology and Ecology

The seeds germinate from January to early March in cooler areas when soil temperatures reach about 59°F; the optimal temperature range is 54° to 68°F. However, if the soil is very moist, seeds can sprout at much higher temperatures. The seeds typically germinate at or very near to the soil surface. Germination can be in large numbers after an irrigation or rain. The deeper the seeds are buried or the drier the soil, the less likely it is that the seeds will germinate or the seedlings will survive. Mature seeds can germinate without a dormancy period. Chickweed can complete its lifecycle in 5 to 6 weeks. When growing without competition from other plants, common chickweed can produce approximately 800 seeds and it takes 7 to 8 years for the seed bank (supply of viable seeds in soil) to be 95% depleted, insuring an infestation for many years.

Management Approaches

Chickweed should be controlled before it flowers. This can be difficult due to the short period between germination and flower production. However, regular monitoring and removal of plants from the site will prevent seeds from developing and accumulating in the soil (seed bank).

Biological Control

Other than grazing by sheep and birds, there are no commercially available biocontrol agents for the chickweed species.

Mechanical and Cultural Control

In small infestations, hand pulling or digging prior to flowering can control common chickweed, and tilling soil can reduce germination. It is important not to only remove the plants from the ground but also remove them from the site; common chickweed can reroot from stem nodes in moist areas.

Chemical Control

Several chemical control options are available for common chickweed control, however common chickweed resistance to some acetolactate synthase (ALS) inhibitors has been reported in Canada and Europe. For a complete list of reports of resistant populations of common chickweed see http://www.weedscience.org/Summary/USpeciesCountry.asp?lstWeedID=168&FmCommonName=Go.

For herbicide recommendations for specific grain rotations and weeds in Montana, please see the MSU Herbicide Chooser Tool.

Examples of herbicides that can be used to manage Common chickweed

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Herbicide Active Ingredient trade name	Mode of Action	Product per Acre	Application Time or Growth Stage
Alfalfa
Pronamide	Microtubule assembly inhibition
*Kerb 50W		1.5 - 2 pounds	Apply during the fall or winter months. Applications may be made post-emergence to established, actively growing or dormant alfalfa or to new plantings after the alfalfa has reached the trifoliate leaf stage.
Imazamox	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Raptor		4 - 6 ounces	Apply when the seedling alfalfa is in the second (2nd) trifoliate stage or larger and when the majority of the weeds are 1-3 inches tall. When applied to alfalfa grown for seed, apply before bud formation. Apply to established alfalfa to dormant or semi-dormant alfalfa, or between cuttings. Applications should be made before 3inches of alfalfa growth or regrowth	Dry Peas
Imazamox	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Raptor		4 ounces	Apply post-emergence prior to bloom stage but after dry peas have at least 3 pairs of leaves. Delay application until the majority of the weeds are 1- to 3- inches tall.
Grass Grown for Seed
Dicamba	Action like indole acetic acid (synthetic auxins)
*Clarity		8 - 24 ounces	Apply 8-16 fluid ounces per treated acre on seedling grass after the crop reaches the 3-5 leaf stage. Apply up to 24 fluid ounces on well-established perennial grass. For best performance, apply when weeds are in the 2-4 leaf stage.
Wheat
Sulfosulfuron	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Maverick		0.67 ounces	Apply post-emergence in fall or spring when common chickweed is actively growing. Apply after wheat emerges but prior to jointing stage.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

References

For more information and images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=common%20chickweed

For more information on common chickweed please see the University of California IPM Online guide for chickweeds. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74129.html