Minecraft wiki entry for Sapling, associated text: When leaves decay, or are broken by any tool except shears, they have a 5% chance of dropping a sapling, except for jungle leaves, which have a 2.5% chance of dropping a sapling. The Fortune enchantment increases the rate to 6.25% (2.78% for jungle leaves) at level I, 8.33% (3.125% for jungle leaves) at level II, and 10% (4.17% for jungle leaves) at level III.