The avocado tree (Persea americana) can grow to heights of 30 to 60 feet. Native to Mexico, the tree is adaptable to most soil types, including clay. There are three types, or races, as they are known, of avocado: Guatemalan, Mexican and West Indian. Each race contains varieties, some hardier than others. Mexican avocados are the ones you generally find in American grocery stores. Planting the seed, or pit, of an avocado will result in a common houseplant.
Remove the avocado pit from the fruit, and wash it under running water. To remove any traces of pulp, scrub it gently with a soft toothbrush. Set the seed on a paper towel to absorb excess moisture.
Fill the planting pot with equal parts of sand and potting soil. Water the soil until the water drains from the bottom of the pot. Allow the pot to drain completely.
Push the avocado seed into the soil until just the top of the seed (the pointed end) is above the surface of the soil.
Place the pot in an area that remains 60 to 70 degrees F. Mist the soil to keep it moist. The seed should sprout within six weeks.