Most Homes Are Dry; With Air Conditioning And Central Heating Pulling Moisture Needed By Plants Out Of The Air. Here'S A Simple Solution: Place Bonsai On A Low Tray With A Layer Of Decorative Rock. Then Water Your Bonsai From Above. Excess Water Collects In The Tray And Slowly Evaporates; Increasing The Humidity Around The Tree And Improving The Growing Environment. Your Bonsai Tree Thrives While Windowsills Stay Dry And Debris-Free. A Tray Can Also Be Used Outdoors To Improve Conditions In Dry Or Windy Sites. Tray Comes With Decorative Rocks.