The avocado is one of the most popular tropical fruit trees in North America. Loved for its dark green foliage and delicious fruits, it has become a favorite for landscapers and gardeners alike. Unfortunately, it is not cold tolerant and therefore cannot be grown outdoors in many areas. Indoor avocado trees offer those in Northern climates the opportunity to enjoy the foliage of the avocado trees. And while it is unusual for an indoor avocado to bear fruit, it does occasionally happen, allowing a fortunate few the chance to harvest their own homegrown fruit.
Select a variety of avocado that is well adapted to container-growing, or which is categorized as "dwarf." These include the Gwen Avocado, the Wurtz or the Whitesell. Each of these are small in stature and are subsequently well suited to container growing. If you cannot find one of these types of avocado seeds, you can simply purchase an avocado from the local supermarket.
Sprout the seed. If you're starting with a whole avocado, remove the pit and gently wash it, to remove any residue. Allow the seed to dry for 24 hours and then insert toothpicks into the seed. Push the toothpicks in about 1/4 inch, circling the pit around the approximate center.
Fill a clean jar with water and place the seed over the mouth of the jar. The toothpicks should hold the pit suspended over the mouth of the jar, with the rounded end in the water and the pointed end exposed to open air. Use enough water to keep the bottom third of the seed immersed.
Place the jar in a warm location, out of direct sunlight. Check the water level every day, adding more as needed. Once the seed begins to sprout, move the jar to a sunny window.
Transfer the seedling when it reaches 12 inches in height. Begin by pruning the growth, cutting the shoots approximately in half. This will produce a stronger, fuller plant. Remove the plant from the jar and transfer it to a large container filled with a combination of potting soil and compost. For ease of movement, you may want to consider a planter with wheels as the tree will undoubtedly get very heavy as it grows.
Move the pot to a location with warmth and good light. If you have windows on the south side of your home, these will be ideal, as they will provide the most light throughout the winter months.
Monitor tree growth and development on a weekly basis, removing any undesirable growth as it occurs. This is very important to the success of your indoor avocado, as even a dwarf avocado tree can grow to 10 feet in height, which is entirely too large for almost any indoor application
Move your tree outdoors for the summer. Place the container in a sunny location, allowing the foliage to enjoy unrestricted access to the rays of the summer sun. When the weather begins to drop below 50 degrees Fahrenheit overnight, bring the tree back indoors for safekeeping.
Wait for the fruits to grow and ripen. It won't happen for everyone, but in case it does- the fruits are ready to harvest when the skin turns color. The color change ranges from yellow to black, depending on the variety. The avocados will not be soft when picked and must be set aside for several weeks after harvesting before they are ready to eat.