Common mallow (Malva neglecta) is a persistent, low-growing nuisance in lawns and gardens. It is often called Cheeseweed because its flattened, disc-shaped fruit capsules resemble small wheels of cheese. Mallow is successful due to its ability to produce a deep, woody taproot and prolific seeds, ensuring its return year after year. This guide provides a strategy for effectively eliminating mallow and implementing long-term prevention measures.
Identifying Mallow and Understanding Its Growth Cycle
Mallow is easily recognized by its distinctive foliage, which grows in a prostrate, or low-spreading, habit close to the ground. The leaves are kidney-shaped to round with scalloped margins and are attached to the stem by long petioles, or leaf stalks. Both the stems and leaves are covered in short, stiff hairs, giving the plant a slightly rough texture.
Mallow often behaves as a summer annual, germinating in the spring and dying in the fall. However, it can also act as a biennial or short-lived perennial in regions with mild winters. In these climates, the plant establishes a persistent, thick taproot during its first year, making it far more difficult to remove later.
The woody taproot makes controlling mature mallow challenging. This deep root system allows the plant to access moisture and nutrients far below the surface, helping it survive drought and stress. Control efforts are most successful when timed before the plant flowers and sets seed, typically from late spring through fall.
Physical and Organic Removal Techniques
For small patches or isolated plants, manual removal offers an effective solution, provided the entire root is extracted. Young mallow plants, especially those with fewer than four true leaves, are the easiest to manage, as their taproots have not yet become woody. Pull these young weeds when the soil is moist, which helps to loosen the soil around the root structure.
When hand-pulling, it is imperative to remove the entire taproot; if the root crown is left behind, the plant can resprout and continue to grow. For established plants, specialized tools such as a dandelion digger or a weed popper can be instrumental in leveraging the tough, deep taproot out of the soil. Simply severing the weed at the soil surface is ineffective for mature plants.
In garden beds, organic methods like smothering and mulching suppress new mallow growth. Applying an opaque barrier, such as cardboard or landscape fabric, followed by a substantial layer of mulch, blocks the light required for germination. For long-term control, maintain a thick layer of organic mulch, such as wood chips or shredded bark, at a depth of three to four inches.
Targeting Mallow with Herbicides
For widespread infestations, use broadleaf herbicides in turfgrass areas. Mallow is best controlled by post-emergent products containing a combination of active ingredients, such as 2,4-D, dicamba, or triclopyr. Using a product that combines two or three of these compounds often provides better results than using a single ingredient alone.
The application must be accurately timed to be most effective. Herbicides work best when the mallow is young and actively growing, before it develops a robust taproot or produces seeds. Applying a post-emergent herbicide when the plant is vigorous allows for better absorption and translocation of the chemical throughout the plant, including down to the root.
Mature mallow plants with fully developed, woody taproots can be highly resistant to many common herbicides. Always read and strictly follow the product label directions for application rates and safety precautions. For prevention, a pre-emergent herbicide applied in early spring can help stop mallow seeds from germinating.
Long-Term Management and Prevention
Establishing a dense, healthy turf is a reliable method for preventing mallow’s return. A thick stand of turfgrass creates competition for light and nutrients, making it difficult for weed seeds to establish. Maintaining a consistent, taller mowing height, ideally between 3 to 4 inches, helps to shade the soil and suppress mallow growth.
Proper watering practices also discourage establishment. Instead of frequent, light sprinklings, water the lawn deeply and less often, aiming for approximately one inch of water per week. This encourages the turfgrass to develop a deep root system, making it more resilient and better able to outcompete mallow and other weeds that prefer moist surface soil.
In garden beds, consistent maintenance of a thick mulch layer prevents the sunlight required for mallow seed germination. Monitoring and quickly removing any new mallow seedlings before they can establish their deep taproot or produce seeds is important. Integrated cultural practices focused on soil health and plant competition are the most sustainable strategies for long-term control.