FAQ: What is the best garden soil to buy?
The best garden soil you can purchase isn’t soil at all, but compost. Adding compost to your existing soil is actually cheaper than buying soil, and it offers so much more than dirt.
As little as 1/8 to 1/4 inch of compost incorporated into the top layer of soil adds organic matter, nutrients, beneficial microbes, etc.
But for a real power punch and some beautiful soil, add compost at a ratio of 1 inch or so of compost for every 3 inches of native soil and mix thoroughly. Use no more than 30% compost in that four-inch layer of enriched garden soil.
However, since most garden plants need at least 12 inches of soil for good root development, you will need to consider adding at least 3 inches of compost to 9 inches of existing soil to achieve 12 inches of amended soil.
To help with your garden planning, we found this article with a chart that includes root depths for common vegetables and herbs.
NOTE: If adding compost to a container or raised bed, hold the compost to 25% of the soil-compost mix.