Fruit Trees can be bought for 2000-4000 gold at Pierre's Shop, excluding Banana Trees and Mango Trees which can be acquired on Ginger Island. They don't die after their season like other crops do, but instead, they don't produce fruit. Fruit tree saplings will grow during any season and do not require watering.
Fruit Trees must be planted with the surrounding tiles empty or else they won't grow (3x3 tile area with the tree planted in the center).
Fruit trees require 28 days to mature, after which they produce one fruit per day when in season. Tree Fertilizer can't be used on fruit tree saplings to speed up gestation times.