A Bonsai Humidity Tray is an essential Bonsai accessory. Bonsai Humidity Trays are used to protect surfaces and maintain moisture levels around Bonsai between watering. To use your Bonsai Humidity Tray, layer pebbles on the tray and place the Bonsai Tree on top of the pebbles. As you water your Bonsai, the excess water will drain from the holes in the bottom of the Bonsai container onto the tray. Keep some water in the tray at all times to provide a humid environment for your Bonsai.