The Gardens now have a broadfork. It’s specifically good for aeration of the soil deep down but also can be used for turning over soil, digging up potatoes, sweet potatoes etc.
Broadforks have two big advantages: number one – they are easy to use. The two handles and the design give leverage that makes them easy to use even for people without lots of upper body strength.
The second advantage though is that broadforks maintain soil structure and avoid harming all the creatures in the soil food web. They avoid compacting soil, upending soil layers, and exposing underground creatures to the sun. A broadfork allows you to soften soil and introduce some air, without destroying the habitat that is supporting all the life that is keeping the soil healthy and fertile. Seeds are less likely to be brought to the surface where they germinate, so there is less weed invasion. Crop plants can get their roots down deeper without losing the benefits of topsoil.
A side benefit too, is that they require no fuel and are very robust, so minimal maintenance and should last a long time.