Solarization method for garden
If you want a new garden spot, here is a good method without any of the back breaking labor. Get clear construction plastic and lay it out where you need it. Anchor it down with bricks, etc.
Now the easy part - let the sun do the work and actually cook the grass, weeds, etc. It will also kill all the weed seed down to about 1 foot.
How long does it take - as long as necessary.
It works - do a search for solarization