Other than Spartan apple, almost all apple trees need a pollenizer. As long as the trees that you choose fall into the same timing for their bloom cycle, they can be used to pollinate each other. Use early bloomers for other early bloomers, mid season bloomers for other mid season bloomers and late bloomers for other late bloomers.I am pretty sure I've found 3 apple trees I'd like to plant. My issue is, 2 of them are listed as pollinizer needed. Can they cross pollinate each other (the 2) or would I need a pollinizing tree for each one?