Create a checklist of all items in the bathroom that need deep cleaning and make the checklist a to-do on your monthly chores list. Bathrooms vary in their setup, but your list should include, at the minimum: 1  Shower and/or bathtub and any grout.  Showerhead.
Marijuana plants function the best when their surroundings maintain a consistent temperature between 70 and 75 degrees Fahrenheit during the daytime, and 50 and 60 degrees Fahrenheit at night.
Schedule spraying for moderate temperature. The effectiveness of Roundup decreases with very low or high temperatures. Choose a day for application with mild temperatures in the 65 to 75 degree F range. Applying herbicide on hot days causes quick evaporation of the weed killer from plant leaves.