Cheeseweed

Common Name(s)

Cheeseweed

Common mallow

Scientific Name

Malva neglecta

Family

Malvaceae (Mallow family)

Reasons for concern

This plant grows in landscapes, gardens, and turf, and detracts from their aesthetic value. It can also serve as a reservoir for a number of plant viruses, including alfalfa mosaic virus, tomato yellow leaf curl, and tomato spotted wilt. It grows close to the soil, preventing desirable native plants from growing, and reducing the plant biodiversity that is so important to pollinators and wildlife

Classification

Non-native

Botanical description

Rounded and bushy herbaceous plant.

Leaves

Seedlings have cotyledons with heart-shaped leaves with smooth edges. First true leaves are geranium-like, hairy, on a long stem, and nearly circular to heart-shaped with 5-7 rounded lobes with crinkly edges. Short hairs appear on leaf surfaces.

Stem(s)

Tough, spreading and low growing. Occasionally upright.

Flowers

White to light pink, which form at ends of stems. Five notched petals with pale striations. Blooms summer through fall.

Seeds

Contained in round fruit which looks like tiny wheel of green cheese with wedge-shaped sections.

Roots

Large, tough taproot, which gets woody as plant matures.

Native to

Europe

Where it grows

Lawns, gardens, roadsides, pastures and disturbed areas. Grows in sun or shade. Found at elevations from 4,000 to 8,000 feet.

Lifecycle

Annual, biennial or short-lived perennial

Reproduction

By seed

Weedy Characteristics

Seeds remain viable in soil for a long time. Deep, stout taproot makes them hard to pull or dig. Dense populations starve nearby plants of sunlight.

Look-alike Plants

]Can be confused with native globemallows (Sphaeralcea spp.). Globemallow species in northern Arizona usually have orange flowers but some species in the state have pink or white flowers. These often have more triangular leaves. Globemallow flowers do not have striations on petals. Stems are taller and more upright.

Control Strategies

Common mallow is best controlled when small. Pull, hoe or dig when plants are young since the taproot is not as large, deep or tough. Consider covering a dense population with a very thick mulch. This will also prevent seed germination. Without sun, plants will eventually die. Frequently monitor previous infestations for new growth. Plant desirable native species to out-compete invasives. Some broadleaf herbicides are effective on young plants and pre-emergence herbicides can be used to control seed germination. Glyphosate is usually not effective. Contact your local county extension office for more information on chemical control.

Gallery

Malva Neglecta (cheeseweed) back of leaf

References

Weed of the week: Cheeseweed (video) Coconino County Extension
A Homeowner’s Guide to Identifying and Managing Common Mallow University of Nevada Cooperative Extension
Mallows University of California Agriculture and Natural Resources IPM – Pests in Gardens and Landscapes