Common mallow

Identification & Biology
Alias' : buttonweed, cheeseplant, cheeseweed, dwarf mallow, roundleaf mallow
Latin Name : Malva neglecta
Category : Terrestrial Plants
Description :
  • Annual, biennial or perennial growing to 0.6 m tall 
  • Leaves are rounded and have five to seven lobes 
  • Branched hairy stems  
  • Flowers are cup shaped, five-petaled, and can range from white to pink to shades of lavender and blue  
  • Woody taproot 

 

Common mallow forms a deep woody taproot and low spreading branches along the ground. It reproduces primarily by seed. Seeds are borne in smooth, round flattened, button-like fruits, which break into single-seeded segments at maturity. Flowers bloom from June to September. Common mallow is often consumed as a food, with its leaves, stalks and seed all being considered edible.  

Common mallow can be easily confused with little mallow (Malva parviflora). These two species can be distinguished by the flower petals and fruit shape. Common mallow flower petals are longer and the fruits are smoother than those of little mallow.  

Habitat

Native to Eurasia, common mallow is often found in cool and damp areas such as marshes and bogs. However, it has adapted to a variety of soil types. It also invades disturbed areas such as cultivated lands, gardens, turf, roadsides and drainage ditches.  

Impact & Risks
  • Common mallow can serve as a major reservoir for pests such as whiteflies and thrips, as well as a number of plant viruses including alfalfa mosaic virus, cotton leaf crumple virus, tomato yellow leaf curl and tomato spotted wilt tospovirus. 
  • Infestations can prevent the establishment of native plants and desirable forage species. 
  • It can be toxic to horses. Although horses are not usually attracted to common mallow, they will eat it in the absence of better forage. Symptoms of common mallow toxicity include muscle twitching, inability to rise, high heart rate and sweating. 
  • Left uncontrolled, common mallow can greatly interfere with machinery used for harvesting crops.   
Prevention & Mitigation

The most effective way to ensure that your lands do not become infested with common mallow is by prevention. Here are some recommendations to prevent invasion: 

  • Maintain your crops and natural lands in a healthy, vigorous condition to ensure a competitive plant community; competitive perennial grasses and forbs utilize water and nutrients that would otherwise be readily available to common mallow. 
  • Regularly patrol your property for common mallow plants and immediately control or remove infestations before seed set.  
  • Immediately re-vegetate disturbed, bare soils with a suitable seed mixture that provides dense, early colonization to prevent weed invasion.  
  • Do not move contaminated soils to a new area.  

 

Treatment & Disposal
  • Pulling, hoeing or digging can be done for small infestations or individual plants, but can be difficult because of the large woody taproot. Hoe or dig when plants are young.  
  • For larger infestations, cultivation can be used to control young plants. 
  • Mowing is not an effective method of control because the plants have viable buds on the stems below the height of the mower blade.  
  • Mulching may prevent regrowth. 
  • Chemical control is also an option. Before applying herbicides, read the label for full use and precautionary instructions.  
  • For further information on the selection and application of chemicals to protect your crop, contact AgriService BC at 1-888-221-7141 or email AgriServiceBC@gov.bc.ca.  
  • There are currently no biocontrol agents available for common mallow in BC. 
Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.