a grimme 3 bedtiller with ridging bodies

How Does A Bedtiller Work?

In the world of vegetable growing, bedtillers play a crucial role in shaping the soil into raised beds, providing an optimal environment for crop growth. These specialized machines, which function as a combination of a rotavator and drill plough combined, are designed to match the wheel track settings of a tractor, ensuring precision and efficiency in the bedforming process.

The Function of a Bedtiller

Bedtillers are essential tools used by vegetable growers to transform ploughed ground into finely tilled-shaped beds. Unlike conventional rotavators, a bedtiller operates within a specified width that matches the tractor’s wheel track settings. This standardized width, often around 72 inches, allows for consistent and uniform bed formation throughout the field.

The Bedtilling Process

A bedtiller typically consists of a tilling rotor and some type of shaping section attached to its rear: either a forming hood or two large drill ploughs called ridging bodies. Forming hoods are responsible for shaping the tilled soil into raised beds, creating the ideal growing conditions for a variety of crops. Ridging bodies shape the soil into large drills, for soil destoner/ decloders to process. A bedtiller is used directly onto ploughed soil.

a grimme single bedtiller with ridging bodies
A Grimme single bedtiller with ridging bodies.

Harvesting crops

For crops where the soil and crop are lifted by the harvester, the soil is usually destoned/decloded so the unwanted stones/clods are not brought in with the crop- such as potatoes.

Bedtillers used for potatoes will be fitted with two large ridger bodies behind the bedtiller. These ridger bodies leave the soil in a large drill shape, ready for the subsequent destoning process.

The destoner, equipped with webs and rubber star wheels, effectively removes stones and clods from the soil, ensuring optimal growing and harvesting conditions for potatoes. Once the soil is prepared, a potato planter will place the potatoes in two rows within the finely tilled bed and shape the soil into two drills per bed using either a forming hood or drill ploughs.

Bedtilling for Other Crops:

While potato growers prioritize destoning to make the separation of the soil from the potatoes at harvesting easier, other vegetables, like leeks, which are harvested by pulling them up out of the soil do not require the same level of soil preparation.

For these crops, a bedtiller fitted with a forming hood is commonly used, this means the soil can be directly sown into immediately after bedtilling.

Single Rotor vs. Twin Rotor Bedtillers:

Bedtillers come in two main variations: single rotor and twin rotor.

a jones engineering 3 bed twin rotor bed former
The underside of a Jones Engineering three-bed twin rotor bedformer with speed blades.

Single rotor bedtillers

Single rotor bedtillers are primarily used for potato beds that will subsequently undergo destoning processes. These bedtillers have one main tilling rotor similar to those found in rotavators.

Twin rotor bedtillers

In contrast, twin rotor bedtillers offer additional advantages for direct sowing after bedtilling.

They feature a secondary tilling rotor located near the rear of the machine. This larger diameter cylinder has short vertical blades, spinning around at speed which effectively till and level the top layer of the bed, making it exceptionally suitable for sowing small seeds.

The finer the soil into which small seeds are planted, the larger the surface area of contact the seed has with the soil, greatly enhancing germination rates. Moreover, the presence of the secondary rotor in twin rotor bedtillers facilitates precision seeding, enabling consistent seed placement at the desired depth, further optimizing germination and growth.

Bedtillers vs Rotavators

It is important to note the distinctions between bedtillers and rotavators.

Wheel track widths

While bedtillers have a fixed width, designed to match specific wheel track centers, rotavators vary in width and are designed to till as wide as the tractor’s horsepower can handle.

Bedtillers are specifically designed to till either one, two, or three beds at a time.

These tilled beds although at exact centre distances apart can then be left as one bed or separated into two or three drills by shape forming hoods that can leave a variable amount of wheel track space at the sides so machinery with wider tyres can be used.

This offers advantages for growers who experience more wet weather, because wider tyres helps to prevent soil compaction and machinery getting stuck during spraying and harvesting.

This shape-forming hood on the back of the Grimme potato planter creates two drills with extra room at the sides for machinery with wide tyres.

Fixed drill widths

In contrast, a rotavator may offer more flexibility in terms of widths but because it cannot form beds of a distinct width means that a conventional drill plough must be used. This will create uniform ridges with fixed wheel widths across all the drills.

Fixed-width drills means machinery is limited to the width of tyres it can use, otherwise, if wider tyres are used they will crush the drill and its contents.

Blades and Gearbox:

Bedtillers utilize a variety of blades depending on the desired tilling effect. Solid bars, similar to those used in rotaspike tillers, and L-shaped blades, commonly found in rotavators, are among the options available.

However, bedtillers have additional blade types known as speed blades and hook tine blades, which are curved blades designed to produce very finely tilled soil. The use of these blades significantly improves the tilling quality, resulting in a finer tilth compared to traditional rotavators.

In terms of power transmission, all bedtillers are fitted with a 1000rpm PTO (power take-off) gearbox. This high-speed gearbox enables the bedtiller to achieve finer soil tillage. In contrast, many conventional rotavators are equipped with a 540rpm gearbox, which does not provide the same level of soil refinement.

Soil Preparation

Bedtillers offer advantages over traditional rotavators, particularly when it comes to preparing the soil for small-seed planting.

Because bedtillers create a finer tilled soil than conventional rotavators this provides an increased surface area for seed-soil contact, greatly enhancing germination rates and overall crop establishment. Additionally, the secondary rotor in twin rotor bedtillers ensures consistent seed depth, resulting in uniform plant emergence and a more homogenous crop stand.

Robust Construction:

Bedtillers are built with extra-strong frames, particularly those fitted with large ridging bodies used for destoning. These robust frames are essential to withstand the significant stresses placed on the bedtiller chassis by the large ridging bodies. The construction of bedtillers is specifically designed to handle these demanding tasks, ensuring durability and longevity.


Bedtillers play a vital role in the field of vegetable growing, offering precise and efficient soil preparation for various crops. Their ability to shape the soil into raised beds at fixed centres with different wheel widths, the presence of secondary rotors for improved seedbed quality, and the utilization of different blades all contribute to higher germination rates and better overall crop establishment. By understanding how bedtillers work and their unique features, vegetable growers can optimize their bedforming processes and achieve successful and productive harvests.