Fruit Trees can be bought for 2000-4000 gold at Pierre's Shop. They don't die after their season like other crops do, but instead, they don't produce fruit. Fruit saplings will grow during any season and do not require water.[1]
Fruit Trees must be planted with the surrounding 8 tiles empty, or else they won't grow.
Fruit trees require 28 days to mature, after which they produce one fruit per day when in season.[1]