There are great rewards to be had by double digging your garden beds. It is a very labor intensive method of improving the gardens soil structure. It involves the improvement of the first 2 feet of the gardens soil.
Double digging is hard work and is not for everyone. If you have health conditions that restrict you to heavy work or back problems I would recommend staying away from this method of gardening.
When double digging it is best to start out small and just work an area that you can handle. It is going to take time so do not try to take on to much because you will only get disgusted and most likely give up on finishing it. I do not want to make this sound like I do not want to make it sound like I am trying to talk you out if if this method to your garden because the benefits that you will get in return will be great. Just take your time.
Several days before you start this project you should mark out the area you want your garden and soak the area with water. Once you have fished that step wait a few days and remove any sod or weeds that are in that area and loosen the first foot of soil with a spade.
The next day you plan on working on your bed you can start by digging and removing a one to two foot wide area of topsoil the width or the length of the garden area, depending on where you are starting. Take this topsoil and stockpile it at the opposite end of the garden from where you are starting. Depending on the size or distance you have to move it a garden cart or wheel barrow may be needed. This stockpile area is where you will end the garden. Pile it on the yard off the garden area on a garden cloth, boards or something that you can easily clean it up from at the end.
Once the topsoil is removed you will need to start loosing the subsoil layer of dirt below where the topsoil was. You can do this by taking a spade and sticking it deep into the soil, twisting or wiggling it until you breakup all the clumps of soil, do this the length or width of where you are working.
Next you will need to spread about a layer of organic matter over the loosened area of subsoil. Once you finish that step it is time to start working the next 1 or 2 foot area that is next to the area you just finished. Simply take the topsoil off the new area and place it on top of the organic matter that you just put in. Continue these steps until you have reached the farthest end of your garden and replace the topsoil that you have stockpiled into the last trench.
Once all the topsoil is all back in place in your garden you need to spread a layer of compost or organic matter over the entire surface of the garden and work it into the top 4 to 6 inches of topsoil.
Now your garden is ready to plant. Remember, only work small areas of a garden that you plan on double digging at one time. The benefits will be great for both you and your plants.