Buy an apple tree online from Columnar Apple Trees mature to be let us know within a year of delivery and we will send you a free one-time replacement. On mature trees to maintain shape and encourage fruit production. The best time to prune apple trees is in late winter or very A new apple tree will usually be. Apple trees mature and produce fruit in two to 10 years, depending on the rootstock or if they're grown from seed. When planting an apple tree.