Root crops grow best in soil that is as fertile and deep as possible. Higher soil organic matter and tilth will yield longer, straighter carrots, heftier rutabagas and prettier parsnips. Double digging is the best technique to maximize bed depth, and early spring or midsummer are great times to prep your beds for spring or fall root crops.
The best way to maximize soil depth and quality is through double digging and ample amendment with lots of organic matter. Double digging is the process of digging deeply to ensure soil is light and porous down deep. Begin by designating a reasonable area to dig. Then with a good, sharp spade, remove the top 8 to 10 inches of soil and place it on a tarp so it can be easily returned to the garden. For the “double” stage of digging, use a hefty garden fork to work up the soil as deeply as possible along the floor of the garden where the soil was removed.
Once light and worked up, add a half and half mix of Black Gold Garden Soil and Black Gold Garden Compost Blend—one bag each for around a 5’ x 5’ garden area. Finally, work in additional bags of soil builder and compost at the same ratio into the soil on the tarp and add it back into your double dug garden.
This method is a lot of work but yields superb root vegetables for years to come. Follow up by planting rows of your favorite fall root crops, like carrots, daikon radishes, rutabagas, beets, and parsnips, and cover the seed lightly with Black Gold Seedling Mix before watering in.