A tiller is an agricultural tool used for breaking up soil, and it can work at soil depths of 8 to 10 inches. It is a powerful tool that can replace a shovel or mattock and is best for large projects that require more digging power, such as breaking up hard, rocky soil for a new garden bed, incorporating heavy clay fertilizers into deeper soil, or digging trenches for irrigation. Tillers can be either front-tine or rear-tine, with rear-tine tillers being relatively easy to maneuver and great for tilling a large area, while front-tine tillers are generally used for smaller gardens that dont have as many roots or weeds to contend with.

In contrast, a cultivator is a piece of agricultural equipment used for secondary tillage. It has smaller tines and a less powerful motor than a tiller, so its not meant to break ground. Cultivators are best for smaller projects that require more maneuvering or finesse, such as mixing up already loosened soil, incorporating fertilizer into topsoil, weeding between crop rows, breaking up crusted soil before irrigation, and working around growing plants without disrupting their roots. Cultivators can be either gas-powered or corded.

In summary, the main difference between a tiller and a cultivator is the size of the equipment and the type of work they are best suited for. Tillers are larger and more powerful, designed for breaking up hard ground and preparing the garden bed for planting, while cultivators are smaller and less powerful, designed for maintaining soil health and working around growing plants.