Double digging is an old practice for improving the drainage and aeration of poor soil. Basically, you remove a row of soil to a depth of about 1 foot, saving the excavated soil on a tarp. Then you loosen the hardpan subsoil (a dense layer of soil, usually found below the uppermost topsoil layer) in that trench with a spading fork. Once that is done you move to the next row, removing 1 foot of topsoil, depositing it in the trench next to it, then loosening the subsoil with a spading fork. You repeat this process until you reach the end of the bed, at which point you use the reserved soil on the tarp to backfill the final trench.
The Best Soil for a Vegetable Garden and Root Crops
Double digging may seem like a lot of work (and it is!) but once it’s done, you won’t have to repeat it. And it’s one way of making a bed more hospitable to root crops such as carrots. Of course, you could also search for a sandy site. Or build a raised bed and avoid the problem altogether.
Raised-bed vegetable gardens solve a number of issues, including our last one. If you’ve got poor soil, you can avoid dealing with it entirely by building raised beds, then filling them with a custom mix of soil ideally suited to what you are growing. Your expense in materials may be a good tradeoff for what you save in labor. Also, raised beds warm up more quickly in spring so you can plant earlier. And they’re not overrun with migrating turf. One drawback: raised beds dry out more quickly than the ground.