A 13.5gm packet of Sedgehammer Plus (which is roughly 0.5oz) is a powerful, selective herbicide containing halosulfuron-methyl, designed to kill nutsedge (yellow and purple) and other weeds like horsetail in turfgrass, ornamentals, and landscapes, mixing one packet into 1 gallon of water for effective coverage with a built-in surfactant for better sticking and no need for extra additives, targeting young, growing weeds for best results. 

• Active Ingredient: Halosulfuron-methyl.
• What it Controls: Primarily yellow and purple nutsedge, but also horsetail, cocklebur, and others.
• Application: Mix one 13.5g (0.5oz) packet with 1 gallon of water and spray on affected areas.
• Surfactant: It's built-in, so no need to add extra wetting agents for better results.
• Timing: Apply to young, actively growing nutsedge for best control.
• Usage: Use the mixture within 24 hours of mixing.