Care should be taken in selecting a herbicide to insure that there will be no residual chemical present that could damage the crop. Cutflowers are usually started from transplants, divisions or tubers, but sometimes are grown in the field from seed. For the most part, pre-emergence herbicides should be applied after transplanting. To achieve the same level of safety, the herbicide usually should not be applied until after plants emerge and are established. Also, in a mixed field of cut flowers all species being grown should be listed on the herbicide label.
Herbicides are available in several formulations.
These can be applied through a tractor mounted sprayer in field or by hand-held backpack sprayers equipped with a spray boom. It is important to get as uniform an application as possible. With a backpack sprayer, maintain a constant foot pace, even spray pressure and uniform nozzle orifices. When applying a herbicide the exact square footage of the area to be treated should be known. Misapplication of the chemical can result in poor weed control or injury to the crop.