The right rotary tiller can make the job of gardening much easier, but if you choose the wrong tiller for the job, it can make your job more difficult.
Tillers range in size from small hand-held models to those weighing several hundred pounds, with corresponding differences in capacity. There are several factors to consider in selecting the best tiller for your job.
Several companies offer small, hand-held rotary tillers, typically with 2-cycle engines (Figure 1). These little tillers have star-shaped blades instead of separate tines. They are suitable for light-duty tilling such as cultivating small vegetable or flower gardens. They are narrow and can get into tight places. They will not till deeply, nor will they handle much surface trash. Other garden tillers range from 3- to 5-hp front-tine models to 8- to 10-hp rear-tine models. Some semi-commercial rear-tine models are even more powerful. The larger units have tilling widths of 20-26 inches and can cut 6-8 inches deep under ideal conditions.
Front or Rear Tines
Rotary tillers can have the tines in front of the wheels (front-tine) (Figure 2) or behind the wheels (rear-tine) (Figure 3). The two styles overlap in size (horsepower and tilling width). The wheels on front-tine models are usually not powered, but the wheels on rear-tine models usually are. The tines are usually covered with a shield on a rear-tine tiller but are exposed on a front-tine tiller.
Larger rear-tine tillers will have the ends of the tine assembly as well as the top shielded. Most rear-tine tillers provide a flap or drag at the rear to keep feet out of the tines and to level the tilled soil. The powered wheels on the rear-tine tillers help hold the tiller back and provide a more uniform speed, while you will have to control the speed of front-tine models by brute force.
Depth control is generally easier with a rear-tine tiller since the depth control drag bar is generally effective. On front-tine models, a drag bar is usually provided, but most depth control comes from how you hold the tiller. With a front-tine tiller, it is almost always necessary to walk right behind the tiller in the freshly tilled ground while fighting to control the machine.
With a rear-tine tiller, it is often possible to walk to one side, controlling the tiller with one hand and thus avoid walking in the tilled soil. Soil tilth is almost always better with a rear-tine tiller. Rear-tine models are more expensive but well worth the extra cost.
Tiller tines can be driven by a shaft or a chain. The clutching mechanism can be an actual clutch, or clutching can be accomplished by slackening a belt drive. Many rear-tine tillers will have two or more forward speeds as well as reverse. In many cases, it is necessary to hold the reverse control in place while going backward, but some tillers allow you to shift into reverse and operate just as you would in forward. The latter design is less safe.
Forward or Reverse Tine Rotation
Most tillers have the tines moving in a forward direction; in other words, the tines rotate in the same direction as the wheels. Some tillers turn the tines in reverse. The manufacturers who offer reverse tines claim that the reverse rotation is more effective at breaking up sod; however, reverse tine rotation should be avoided from the safety standpoint. With forward-rotating tines, if the tines "grab" on a root, rock, stump, etc., the tiller will jump forward - thus away from you.
With reverse rotation, if the tines "grab" on anything, the tiller will jump backward - with the rotating tines coming at your feet and legs! Also, if you are maneuvering in tight quarters -- in a fence corner or next to a building -- the tiller can come back at you, pin you against the obstacle and injure you. Forward rotation is much safer, and you should not purchase or use a reverse-rotation model. Reverse-tine rotation should be used only on tractor-mounted tillers.
Tillers, like other lawn and garden equipment, are available in different levels of quality from different manufacturers. A quality tiller can easily cost two to three times as much as a comparably sized cheap tiller. Since tillers work hard under adverse conditions, a high-quality model is generally a good investment.
There are big differences in the ergonomics of tillers. Some tillers that at first seem to be similar may, in fact, have different ergonomics. Some clutches are much easier to use than others; some reverse mechanisms are much easier to engage than others; some depth controls are easy to move and some require tools and a struggle; some operator presence controls (OPCs) are easy to use and some are not. Try out a tiller or talk to an owner before buying a tiller. It is hard to evaluate ergonomics while looking at a tiller in a store (or a catalog); it takes personal experience to separate the good designs from the awkward designs.
Remember, if you have a small garden you may be better off with a good garden spade and a scuffle hoe and thus eliminate the cost and maintenance hassles of a tiller. If you really do need a tiller, a rear-tine model is much easier to use and does a better job. A small, hand-held tiller may be satisfactory for small jobs.