The seed of an avocado contains a fist-sized seed that will sprout quite easily. Because of this, a popular science activity among younger children is to get an avocado seed to sprout in a container of water. Avocado seeds can be planted in a container and will produce a tree that grows well indoors. A seed-grown tree will not mature quickly, and may not produce fruit for up to 15 years.
Mix a potting soil that contains 1 part peat moss, 1 part sand and 1 part compost.
Cut a square piece of window screening that is slightly larger than the drainage hole of your container.
Place the screening over the drainage hole of the container and fill the container with the potting mix.
Rinse the avocado pit to remove any fruit meat from the exterior of the pit. Scrub the surface with a scrubbing pad to remove the paper shell of the pit.
Hollow out a depression in the center of the soil in the container. Place the large end of the egg-shaped pit into the depression and cover with soil so that the pit is halfway buried.
Water the seed so that the soil is as damp as a wrung out sponge. The pit will begin to grow roots in a few weeks and the top of the pit will split open as the trunk of the tree emerges. Place the tree in a south-facing window where it will receive enough sunlight. Supplement the sunlight with plant grow lights.
Check the container daily and water as the soil dries out. Use a liquid balanced fertilizer (10-10-10). Transplant the avocado into larger containers before the plant becomes root bound.