If your garden gets too large for practical hand cultivation, and is too small to justify a large garden tractor or small farm tractor, what you need is a rotary tiller. The tiller replaces both spade and hoe, and can replace rake and cultivator too, with a little ingenuity. A tiller, run shallowly between rows, makes a weed cultivator without equal.
Because of its versatility, the tiller is probably the most popular garden tool made today. But to determine whether you can economically justify purchasing one, you should compare costs and the amount of food your garden produces.
Tillers are either rear-mounted or front-mounted. With a front-mounted tiller, you push down on the handles to make it dig deeper, the same as the rear-mounted, though the principles involved are different. When you sock the "brake" of the front-mounted tiller into the ground, the tiller can't go forward and the blade continues to turn in place, going deeper into the soil. If the soil is hard, the tiller blades will bounce off it, causing the vibrations that after an hour or two can tire you out. The rear-mounted tiller won't vibrate when the going gets tough, but if you try to force it to bite into tough soil, it will lunge ahead, dragging you with it.
