The garden power tool known as a roto tiller, or rototiller, is available from several manufacturers and in many different designs. It cultivates or pulverizes the soil, usually with L-shaped steel tines or blades that rotate rapidly around a horizontal axle. As the tines are lowered into the soil, they cut surface vegetation into tiny pieces and eventually produce a smooth seedbed.
The earliest rototillers were huge steam-powered machines the size of large farm tractors. The leading European inventor was Konrad von Meyenburg, while, quite independently, Arthur C. Howard was building rototiller prototypes in Australia. The first small walk-behind rototiller was patented by von Meyenburg in 1936.
Until the invention of the rototiller, large areas of soil were broken up and cultivated by horse-drawn implements, while garden-size plots were dug and raked with hand tools. As gas engines improved in reliability and became available in smaller sizes, the usefulness of small walk-behind rototillers was quickly recognized by home gardeners. Small farmers who operated market gardens also found the machines useful.
There are now three basic types of rototiller. The smallest machines, such as the Mantis Tiller and its imitators, consist of a very small engine mounted directly over a set of toothed steel disks that rotate, churning the soil and moving the machine forward. Larger machines have L-shaped tines mounted on a horizontal axle and placed in front of the engine. These machines have rubber-tired wheels which carry the machine but do not propel it. Of similar size, although often larger, rear-tine rototillers have the tines mounted behind the engine, which powers the tines and propels the machine forward on fairly large rubber-tired wheels. The largest rototillers are mounted behind farm tractors.
The group known as mini-tillers include those made by Mantis, Honda and Sears Craftsman. Front-tine rototillers include Ariens, Sears Craftsman, Poulan and Husqvarna. Rear-tine tillers are made by Troy-Bilt, MTD, Husqvarna, Honda and BCS, among others.
Rototillers are useful for breaking new ground and preparing a fine seedbed. However, deep rototilling disrupts or destroys billions of soil microorganisms that contribute to soil health and successful plant growth. Experts recommend that deep rototilling be reduced to no more than once a year or eliminated altogether. Very shallow rototilling, to a depth of three of four inches, is less harmful and still effective in controlling weeds and preparing seedbeds.