Photo: Ohio State Weed Lab, The Ohio State University, Bugwood.org common mallow (Malva neglecta)
Common mallow (Malva neglecta) produces white flowers from spring to early fall and reproduces by seeds that can germinate throughout the growing season. The fruits form on the long flower stalks. They are shaped like a button or wheel of cheese, hence one of the other common name names for mallow is cheese-weed. Seedlings have round, hairy leaves that grow in a basal rosette. They have alternate placement on long petioles. When the plant matures, the leaves maintain the alternate placement. They are palmately veined and round with toothed margins born on long petioles. All foliar parts have hairs. Branching is done at the ground, but the plants can reach a height of over a foot. The stems can persist into winter and sometimes the crowns survive and the plant regrows in the spring.
Mallow has a taproot along with a fibrous secondary root system. It is difficult to pull by hand without using a tool. This plant can be considered a weed in turfgrass and landscape beds, though it is most common in low-maintenance areas. Pre-emergent herbicides include: flumioxazin (SureGuard), oxyfluorfen (Goal, nursery only), oxyfluorfen+trifluralin (Harrel’s 75), and oxadiazon (Ronstar).
For post-emergent applications, non-selective herbicides that contain glufosinate-ammonium (Finale) or glyphosate (Roundup and others) are possibilities if the mallow is not surrounded by non-target plants. Other post-emergents include flumioxazin (SureGuard), oxyfluorfen (Goal, nursery only). In turfgrass, post-emergent herbicides containing mixtures of 2,4-D, dicamba, MCPP, or MCPA should provide adequate control; products that contain triclopyr, fluroxypyr, and quinclorac as one of the ingredients in a two- or three-combination herbicide will also work.
As with any pesticide application, read the label for specific usage information.