Collect your yucca seed from an adult yucca tree. You may also purchase yucca seed from a local gardening shop. Place the seed in a bowl filled with water. Soak the seed overnight to allow it to soften. This makes germination easier.
Prepare your yucca tree pot. Pour potting soil into the peat pot, leaving approximately 2 inches of the pot unfilled.
Dig a hole in the center of the peat pot for the yucca seed. The hole should be approximately one-half inch deep. Put the yucca seed in the hole. Cover the seed with potting soil.
Pour water into the potting soil to help germinate the seed. Pour enough water to fill one inch of the peat pot.
Place the peat pot in direct sunlight in an environment with a temperature range between 60 and 70 degrees Fahrenheit.
Wait approximately three weeks for the yucca seed to germinate. During this time, water the potting soil every few days to keep the soil moist. Your young Joshua tree should emerge from the potting soil within a month.