How big must a lychee tree be to produce fruit?

Lychee (Litchi chinensis) trees typically start bearing fruit when they are around 3 to 4 years old. Once mature, they can grow up to 10 to 40 feet (3 to 12 meters) tall. The size of the tree doesn't necessarily dictate when it will start fruiting, as other factors such as climate, soil conditions, and proper care also affect fruit production.