Dan writes
How long it takes duckweed to die after treatment with Reward Landscape and Aquatic Herbicide depends on when applications were started. Duckweed can multiple every day so can take multiple applications to get control of. What is sprayed should die but anything missed can start to grow again in a few days. Treatments should begin as soon as the duckweed starts to grow in the spring or early summer in temps between 68-86 degrees is ideal.
Answer last updated on: 04/27/2017
