Cherry saplings won't grow past stage 1 if they are close to a regular lantern. Placing soul lanterns, torches, flowers, other cherry saplings, bamboo, and pathways 1-3 blocks from sapling does not hinder growth. The cherry saplings start at stage zero and no matter how much bone meal is placed onto the sapling, it will not grow past stage 1. As long as the regular lanterns are placed near the sapling by the time the sapling reaches stage 1, the sapling wont grow into a tree. I am unsure of what is so special about regular laterns compared to torches and soul lanterns in this case?