dichlobenil (Casoron 4G)
Rate 4 to 8 lb ai/A; 10 lb ai/A for nutsedge (100 to 200 lb/A Casoron; 250 lb/A Casoron for nutsedge)
Time Treat area before containers are set in midwinter when temperatures are cold and rain is expected immediately after application to activate herbicide and prevent loss by volatility.
Site of action Group 20: inhibits cell wall synthesis Site A
Chemical family Nitrile
glufosinate ammonium (Finale)
Spot or directed spray between and around containers only
Rate 1 to 1.5 lb ai/A (4 to 6 quarts/A Finale)
Time Apply around containers to thoroughly cover actively growing weeds.
Remarks A postemergence, partially systemic herbicide. Avoid all contact with foliage and green bark of desirable crops.
Site of action Group 10: glutamine synthetase inhibitor
Chemical family Phosphinic acid
oryzalin (Surflan)
Rate 2 to 4 lb ai/A
Time Apply any time to a weed-free area beneath and around container-grown stock listed on label.
Remarks Inhibits cell division or mitosis primarily in roots. Roots growing from pot drainage holes are pruned without crop injury because the herbicide does not translocate upward in the plant.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
pelargonic acid (Scythe)
Rate 3 to 5% solution to control annual weeds, mosses and cryptogams; 5 to 7% solution for burndown of perennial herbaceous plants; 7 to 10% solution for maximum vegetative burndown, edging, or foliar trimming.
Time Apply to thoroughly wet weed foliage as a directed spray around containers. Most effective when temperature is above 65°F.
Remarks Avoid contact with desirable vegetation. Disrupts cell membranes, causing leakage and symptoms of leaf burn.
Site of action Group 26: unknown
Chemical family Carboxylic acid