I call it The Beast. It's all steel, 16" tines and weighs almost 30 lbs. It'll really rip up roots. Can't remember were I ordered it from. Maybe some farm & garden tool place. I've had it a long time and now use it to loosen up the beds instead of running the tiller through them. It loosens the soil deep down but doesn't upset the soil structure too much.
It'll do a number on Bermuda grass in the beds too. It loosens deeply enough that when you pull a clump of Bermuda out, most all the roots come out too. If any pieces pop up later they come out easily because of the loose soil.
Who needs a gym membership when you work a garden and use a Beast?
