You can mix all kinds of plant waste in a compost heap. In time, the heap rots down to form a dark, rich, crumbly, soil-conditioner. The finished product should have no strong odour, but if things go wrong you can end up with evil-smelling mush. To prevent this, introduce air to the mix. An aerator is a tool that stirs up the heap so air can penetrate. You can make your own aerator from simple materials. It is particularly good for aerating small compost bins, where other tools will not fit.
Find the height of your compost bin or compost heap, using a measuring tape.
Cut a piece of PVC pipe to the same height as your compost heap, using a small saw.
Drill holes at 2-inch intervals along the length of the pipe and all around its circumference, using a drill and a 1/4-inch bit.
Shape the end of a 1/16-inch diameter iron rod into a hook by knocking the end of the rod into an "L" shape with a hammer and then bending the foot of the "L" with pliers. The hook should fit comfortably inside the PVC pipe. The iron rod should be long enough to reach to the bottom of the pipe.
Stand the PVC pipe upright on top of the compost heap. Push the pipe down into the compost until you've set it firmly.
Lay a piece of timber, about 2-feet long by 1/2-inch thick over the open mouth of the pipe. Strike the timber hard with a hammer to drive the pipe to the bottom of the compost.
Lift the pipe up a little to loosen the compost around it.
Insert the iron rod into the pipe and push the hook down to the bottom. Rotate the rod to turn the hook in the compacted compost at the bottom of the heap.
Pull the pipe out of the compost heap. Insert it again in a new position, and use the hook to break up the compacted material at the bottom. Keep going until you have covered the whole heap with air holes.
Leave the pipe thrust into the centre of the heap after aerating the compose. This will encourage the air to circulate, speeding up the composting process.