The metal and plastic screens that help keep mosquitoes and other warm-weather pests out of the house this time of year can also prevent soil from washing out of planters during rain or irrigation. Unroll a piece of lightweight screening and set your flowerpot on top. Cut the screen to fit, working around the pot's bottom with scissors (for plastic screens) or tin snips (for the metal kind). Fit the screen inside the pot to cover the drain holes, and then add soil.
Soil-Saving Plant Screen
Martha Stewart Living, June 2008