Leaves that you place are the exact same as leaves that grow naturally on trees – there is no distinction (in the code) between themEdit: As of Minecraft Beta 1. The leaves that you place (and leaves on natural trees) will not8, blocks placed manually by the player don't decay as long as, even if they arearen't within 4 blocks of a logWood block.
Leaves that you place are the exact same as leaves that grow naturally on trees – there is no distinction (in the code) between them. The leaves that you place (and leaves on natural trees) will not decay as long as they are within 4 blocks of a log block.