Avocado trees are fun and easy to start indoors from avocados you buy at the grocery store. The first step getting the pit out of the fruit, and recognizing which side of the seed is up and which is down. Many seeds are tapered with the broader end being the bottom. If your pit has split and has a root already started, be careful not to break the root, and don’t break the seed in two, because it won’t grow if broken.
Avocado plants can be started in soil or water. To start it in soil, soak the pit overnight in water (if it isn’t already sprouting a root), then plant the seed large end down in a pot in well draining soil. The pit should be placed so that the pointed end is about one-half inch above the soil surface.
To start the seed in water, place three or four toothpicks in the side of the seed about half-way down the seed. Then, place the seed, flat end down, in a container, and add enough water to cover the lower half of the seed.
Put the container (soil or water) in a sunny window. Add water as needed to keep the bottom half of the seed in water at all times and water the potting mix as needed. After a few weeks, a small root will appear in the water and signs of a small, tender shoot will appear at the pointed end. Later, when the stem pushes through the top of the seed, plant the seed in a well-drained potting medium.
Avocado plants will grow with water, fertilizer and indirect bright light. Water the plant often enough to keep the soil evenly moist. When an avocado plant is over-watered, it develops curled leaves and soft stems. When under-watered, it wilts and develops dried leaves, which eventually fall off. Give the plant a small amount of houseplant fertilizer every three months.
Avocado plants eventually grow into trees that require lots of space to grow. If your home is small, you may want to start a new plant every three or four years. However, it may take as long as 20 years or more for your tree to bear fruit.