Fruit The fruit is oval or round, green when unripe, and yellow when ripe. The pulp is greenish and the pith is white. Flavor Sweet lemons have a milder flavor than regular lemons, making them popular for juicing and drinks. Climate Sweet lemon trees grow best in warm, sunny environments with well-drained soil. Growing Sweet lemon trees can grow up to 26 ft tall and begin bearing fruit after 5?7 years. They are propagated by seed. Uses Sweet lemons are a rich source of vitamin C and are often used in cooking and as a natural remedy.