The idea of do-dig gardening was developed by an Australian named Esther Deans. It was originally both developed both as a labor saving idea, and a method to rejuvenate badly depleted soil in a vegetable garden.
The process involves starting with layers of newspaper, and by adding lucerne hay, straw and compost in succeeding layers, you can create a growing medium without resorting to heavy digging, and one that is rich in nutrients and which will simplify weeding and encourage your much desired plants to grow. The layers compost together, and greatly encourage earthworms. The gardens are maintained by adding manure, compost, etc., and should not be dug up, as this will undo the good work. I have used this approach to creating vegetable gardens, and it certainly does work.
The principle of not digging has sound foundations. Excessive cultivation of the soil, especially when very wet or very dry, will damage the structure of the soil, and lead to compaction. Such excessive cultivation can also discourage the earthworms, and they are the best free labor a gardener has.
Some followers of permaculture and organic gardening have translated no-dig into never-dig, which I believe is sadly mistaken. If you start with a base soil that is badly compacted, then your no-dig garden will initially work well, but you may find your garden does not continue to perform well. The fertile layer you have built up will encourage the earthworms, but we do know that the worms need to shelter from excessively hot, dry, cold or wet conditions. They have been found to seek shelter from extreme conditions by burrowing more deeply into the soil, sometime many feet down. If they cannot shelter in this way, it is my contention that they will die out or move out.
My belief is that an initial cultivation of the soil before you apply the no-dig system will guarantee a better environment for the worms, and thus a better garden for growing your plants, over the longer term.
By all means give the no-dig approach a try – you will be pleased with the result.