Eggplant trees grow 2 to 6 feet tall. The leaves on the tree are normally green or deep green with purple, or brownish-purple veins going through them. The underside of the leaves are densely covered with wooly hairs, while the upper surface is soft to touch and fuzzy. When the eggplant grows about 6 to 9 inches and its skin is glossy, you can begin harvesting.