Here is a simple diagram that rocks pebbles in the bottom of your pot creates a 'perched water table' closer to the roots which increases the chance of rot. It's a myth that Jiffy Seed Starting Tray Plastic Plant Tray Sold at Ferry Morse Bottom Watering Your Plants (Ever Heard of It!?) Vintage Revivals Covering Drainage Holes in Pots How to Keep Soil from Washing Out What can I do to help my palm plant after changing the potting mix?