When you grow a sapling with a dispenser with bonemeal, the green particles are on the dispenser, which it should be on the sapling.

gatharian added:
Steps to reproduce:
-Place a dispenser, lever, and sappling just like the picture.
-Place bonemeal inside the dispenser.
-Click the lever a few times.
Depending on what direction the dispenser is facing, green particles show around the item instead of the sappling.