Easy to propagate and fast growing, the avocado makes an excellent indoor plant, but don’t expect it to bear fruit. Remove the pit from the fruit, clean it with lukewarm water and insert three or four toothpicks into its sides. Rest the toothpicks on the rim of a glass so that the pit is suspended blunt end down. Add water to barely cover the lower end of the pit. Check the water level daily. Roots should appear in 2 to 4 weeks, but it may take longer. Keep the pit in a warm, draft-free spot away from strong light for a few more weeks until the roots are well developed.
When the roots begin to spread and look bushy, plant the avocado in potting soil in a 4- or 5-inch pot. Set the pit deep enough for the soil to cover half of it. Water with lukewarm water, keeping the soil moist but not soggy. Caring for the plant As the plant develops, the seed splits and a stem with tiny leaves pushes up. You can then move the plant to a place where it will get direct sunlight or bright light at least 4 hours a day. Or put it under two 100-watt bulbs or a frosted white fluorescent tube. Feed the plank liquid houseplant fertilizer once a month.
Without pruning, an avocado becomes spindly and may grow excessively tall. For a bushy, compact plank, cut the main stem back half-way when it is 6 to 7 inches tall, even if it is skill growing in water. New branches will sprout below the cut. To keep an older avocado plank from growing too tall, prune the main stem to the desired height. Encourage branches to sprout from the lower trunk by trimming back the upper branches parkway. Also cut away lopsided, asymmetrical growth.