Some herbicides, such as Ornamental Weedgrass Control, may include a statement on the label which allows a grower to use the herbicide on an ornamental species not listed on the label, provided that the grower makes a trial application of the product at the recommended rate to a small number of plants in order to determine if the product causes injury to the tested species. For palms, growers should check for injury for at least 10 months after application, since it may take this long for injury symptoms to develop. The only postemergent herbicides specifically labeled for use in palm nurseries are Fusilade II, Ornamec 170, and Vantage. Check the labels of these grass herbicides to determine whether they must be applied as a directed spray. Diquat, Reward, and Scythe are contact herbicides which only kill the above-ground portion of the weed.
Contact herbicides are most effective on annuals.
Finale and Roundup are translocated throughout the plant. They will kill annual and perennial broadleaf weeds, grasses, and sedges. Although both of these products are quite safe for use as directed sprays around palms, some Phoenix species have been known to be injured by Roundup applications contacting their root system. Should injury occur, palms will usually grow out of any symptoms within a couple of months. Additional information about these herbicides can be found in ENH-95 Postemergent Herbicides for Use in Ornamentals.