Indoor avocado plants started with seed will eventually turn into an attractive little specimen with glossy, oval leaves 4 to 8 inches long. But it's unlikely your tree will ever bear fruit, or the fruit most likely won't resemble the original.
The avocado plant can grow up to 30 to 60 feet in the landscape; potted plants can be pruned to remain small. When avocado is grown as a houseplant, it is often grown from seed (the fruit pits) that can be sprouted in water or directly in potting soil. Established plants will do best in sunny windows. Fertilize them regularly in spring and summer with a balanced granular fertilizer. Avocados grown indoors are mostly novelty plants. If you want it to bear fruit and turn into the tree it really is, you'll have to move your avocado outside if you live in a warmer climate.