The Deep Bed system is sometimes referred to as Raised Bed though that method bears some differences. I’ll present both of these so you can decide which one is best for your own unique situation.
So first of all: Deep bed gardening.
The Basics.
The idea is that with a deep bed system the earth in the beds is loosened to remove any compaction present. Paths are dug down slightly and the rich top soil dug up from path areas is spread out over the loosened soil of the bed.
In this establishing phase, organic material is also added and often manure is spread out on top and then again covered by a layer of dead mulch (organic material on top of the soil)
After establishment you will never set foot on the bed area! This would lead to compaction and would defy the point of you having made it!
The loose structure and organic material means that the bed soaks up water while still being well-draining (a quality that most of our cultivated plants need in order to flourish)
Roots reach down deep instead of searching in the top layers for nutrients and water. This means you can plant up to four times more tightly than you could in your traditional vegetable patch. This leads to a well-covered soil, which subsequently leads to less weeding!
The dead mulch on the surface is continually topped up, stopping weed seeds from being able to germinate. Again…less weeding! Great. The worms will drag this organic matter down into the soil where they eat it and leave behind their castings (an excellent soil enhancer) Their movements further aerate and improve soil structure. In the abscene of tilling, life in the soil can flourish, and that means your plants can too.
Advantages of no-dig deep bed gardening.
- When beds are established you can get away with never digging them again!
- The bed becomes raised making manual work easier.
- Soil is not compacted meaning plant roots can reach down deep for water and nutrients
Permaculture Learning 