Two to four times per year you will want to empty the compost tube. To remove worm castings, untwist the wing nut at the bottom of the compost tube and remove the plug. Castings will then fall into the receptacle for easy collection. You can add the castings directly back into the Tower, or spread them in other gardens and pots you may have. The most degraded compost should be near the bottom, it's healthy to return a portion of compost to the tube!