Supplies

• Gather two large trash bags, a pair of garden gloves, a garden shovel, a ladder, bucket, household bleach, water hose (with a sprayer), scrub brush, two clean rags or shop towels and a roll of paper towels. If your window boxes are home to insects, locate a can of insecticide to spray the boxes before you start the cleaning process. You may want to wear old clothes to keep from staining a outfit that you like.
  
  

Removing and Dumping the Boxes

• Remove each window box from your house and place it on a flat surface. Use a sturdy ladder to remove any boxes that are on a second or higher floor of your home.
  
  Empty the contents of each box into a trash bag. Use a garden shovel to break free any caked-on and compressed potting soil. Wear garden gloves to protect your hands.
  
  

Mixing a Cleaning Solution

• Mix 1 cup of household bleach and 1 gallon of water in a bucket. Stir the mixture with a scrub brush.
  
  

Cleaning the Boxes

• Spray each window box with water to remove any loose dirt and dust. Then pour about a cup of the cleaning solution into each window box. Let the solution sit for five minutes. Scrub each window box with the brush. Don't forget to scrub the sides and outside of the box. Apply another cup of cleaning solution to any stubborn stains. Continue scrubbing until each window box is clean.
  
  Rinse each window box by spraying it with the water hose. Let the window boxes dry in the sun for one full day.
  
  

Tips

• Before reinstalling the window boxes, spray them with a insecticide to kill any insects that may be hiding out under or in the boxes. If the paint on any of your window boxes is chipping or peeling, scrape off the old paint and use exterior house paint to repaint the boxes.