Agriculture: Floriculture and Ornamental Nurseries Pest Management Guidelines

Special Weed Problems for Field-Grown Trees and Shrubs

LITTLE MALLOW (Cheeseweed)

Cheeseweed is a winter annual or biennial that forms hard seed that can remain dormant for long periods of time. It generally germinates in fall after rainfall or an irrigation, but it may germinate any time during winter and spring. The germinating seed is controlled by most preemergence herbicides, especially oxadiazon and oxyfluorfen. Flumioxazin, indaziflam, and isoxaben are also effective. Oxyfluorfen is also effective applied postemergence to the young plant. Glyphosate is not very effective against this weed.

YELLOW NUTSEDGE

Yellow nutsedge, sometimes call nutgrass, is a perennial sedge that is often confused with a grass. Fumigation before planting is usually effective in controlling this weed. Repeat applications of glyphosate (before the five-leaf stage when new tubers are formed) will reduce populations over time. Bentazon (Broadloom T&O) may be used around some tree species. If the area is left fallow, halosulfuron can be used and then the crop can be planted the next season. Most preemergence herbicides do not control nutsedge, but metolachlor (Pennant) will suppress sprouting of the tubers. Soil solarization will reduce yellow nutsedge but will not eradicate it.

Text Updated: 07/20