tedder

A tedder is a trailing or mounted implement pulled behind a tractor that lifts, fluffs, and spreads newly cut hay across the ground. Its job is purely mechanical: to break up dense swaths, expose wet inner layers to sun and air, and accelerate drying. A tedder typically runs at ground speed of 8 to 12 kilometers per hour and can cover 6 to 8 meters of swath width in a single pass, depending on the model and number of rotors.

Most tedders use rotating tines, usually four to six curved metal fingers mounted on horizontal shafts that spin at 300 to 600 revolutions per minute. As the implement moves forward, these spinning tines comb through the hay, lifting it off the ground and scattering it into a loose, aerated layer. Some models employ a single wide rotor; others use paired rotors for finer control. The tines are spring-loaded or fixed steel, and wear is predictable: tines bend, break, or lose grip after 200 to 400 working hours, depending on stalk thickness and soil contact.

Timing matters sharply. Hay cut in the morning can be tedded once or twice by evening to reduce moisture from around 70 percent to below 50 percent. Poor tedding, or tedding too late when dew falls, negates the work. Over-vigorous tedding on heavy clay soil can push leaves (the highest-protein part) into the earth or separate them from stems entirely, wasting feed value. Rows are typically tedded back into a loose swath, then later raked and baled.

Why the name

The word tedder comes from an old sense of the verb ted, meaning to spread for drying, itself of Scandinavian origin. The practice is ancient, but mechanical tedders arrived in the 19th century. Early machines were ground-driven, using wheels to turn the rotor; modern ones are almost always PTO-driven (power take-off), receiving power directly from the tractor's shaft, which allows independent control of rotor speed regardless of forward speed.

Tedders sit in the middle rank of hay equipment, after the mower and before the rake. In high-rainfall or maritime climates with short windows of good drying weather, a tedder is essential; in hot, dry inland zones with low humidity, farmers may skip tedding altogether and simply rake dried hay directly into windows. Ground-driven tedders, still used in parts of Europe, are cheaper and simpler but less controllable; PTO models dominate commercial operations in North America and industrialized agriculture generally.