HPIPM:Common mallow

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Rosanae
Order	Malvales
Family	Malvaceae
Genus	Malva

Scientific Name

Malva neglecta

Common Name

common mallow

Common mallow(Malva neglecta)

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

Identification and Life Cycle

Common mallow (Malva neglecta), in the mallow family (Malvaceae), is also called buttonweed, cheeseplant, and cheeseweed. Common mallow can be an annual, winter annual (depending on location), or biennial plant. Common mallow has stems that originate from a deep tap root and are low-spreading with branches reaching from a few inches to almost two feet long. Leaves are palmately veined, with the veins originating at the petiole and radiating outward, and ¾ to 3½ inches in diameter. The leaves are nearly circular in outline, with a heart-shaped base and five to seven rounded lobes. The flowers are borne either singly or in clusters in the leaf axils and are formed in midsummer. Each blossom has five white or pinkish lavender petals with notched tips. The petals are about twice the length of the sepals (the green, leaf-like structures which enclose the bud). Seeds are borne in smooth, round flattened, button-like fruits, which break into single-seeded segments at maturity. The seed shape is where this plant gets its common name of buttonweed or cheeseweed.

Habitats

Common Mallow occurs in sunny places that are usually mesic to slightly dry. Growth is more luxuriant in fertile loamy soil, but it is adaptable to different soil types. Habitats include cropland, abandoned fields, farm lots, vacant lots, areas along roads and railroads, edges of yards, and gardens. Highly disturbed areas are preferred, and the invasive potential of this species to natural habitats is low.

Impacts

Dense populations of common mallow can decrease crop yields. Left uncontrolled, mallow plants can greatly interfere with the machinery used for harvesting crops. Common mallow can be a refuge for whiteflies and thrips, and can serve as a reservoir for a number of plant viruses including alfalfa mosaic virus, cotton leaf crumple virus, tomato yellow leaf curl, and tomato spotted wilt tospovirus. Whiteflies and thrips can vector these viruses from the surrounding weeds to the crop.

Biology and Ecology

Common mallow reproduces only from seed. The primary months of growth for common mallow are April through November. Seeds germinate continuously during this time. Flowers appear from May until October.

Biological Control

Some research has been directed towards developing a fungus, Colletotrichum gloeosporioides f. sp. malvae, for control of another weedy mallow (Malva pusilla) with limited success. However, there are no commercially available biocontrols for common mallow.

Mechanical and Cultural Control

Cultivation (roto-tilling or hoeing) will eliminate common mallow plants, especially if the entire plant and root is destroyed. Careful digging is useful to manage weed populations.

Chemical Control

There are several herbicides listed for control of this weed. 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 mallow

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
Imazethapyr	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Pursuit		4 ounces	Apply when the seedling alfalfa is in the second trifoliate stage or larger and when the majority of the weeds are 1 to 3 inches. When applied to alfalfa grown for seed, apply before bud formation. Apply to established alfalfa in the fall, in the spring to dormant or semi-dormant alfalfa (less than 3 inches of regrowth), or between cuttings. Any application should be made before significant alfalfa growth or regrowth (3 inches).
Grass Grown for Seed
Dicamba	Action like indole acetic acid (synthetic auxins)
*Clarity		8 64 ounes	Apply 8 - 16 fluid ounces on seedling grass after the crop reaches the 3 - 5 leaf stage. Apply up to 64 fluid ounces on well-established perennial grass. For best performance, apply when weeds are in the 2 - 4 leaf stage
Wheat
Dicamba	Action like indole acetic acid (synthetic auxins)
*Banvel		2 - 4 ounces	Apply to fall seeded wheat before wheat reaches the jointing stage, apply to spring seeded wheat prior to the 6-leaf stage. Apply when weeds are in the 2-3 leaf stage.
Barley
Dicamba	Action like indole acetic acid (synthetic auxins)
*Banvel		2 - 4 ounces	Apply to fall seeded before the jointing stage and to spring seeded barley before the 4 leaf stage. Apply when weeds are in the 2-3 leaf 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.