Double Pack Humidity Tray for Bonsai , Orchids, Other Plants HT-101 H-2 1/4 x L-13 1/2 x W-10 1/2'by 2 HT-101 H-2 1/4" x L-13 1/2" x W-10 1/2" Black Tray Made from rigid polystyrene, since most plant pots have holes in the bottom for drainage, the humidity / drip tray will protect the surface of whatever you are putting the plant on. You should leave a little water in the tray all the time so that as the water in the tray evaporates, it will create a constant humid environment for the plant and help offset the loss of the loss of moisture through the leaves. Instead of taking the plant to the sink to water it, you can simply water the plant in place. When watering in this way, pour water on top of the plant pot base slowly until it penetrates the media and the excess water comes out of the holes in the bottom of the pot. Save on shipping cost with the double pack.