Most plants will grow within the space you allow them. They’ll survive with a minimum of soil depth, but they’ll thrive if you give them as much room as possible for their roots to branch out and breathe.
If you’re getting a garden bed ready for planting, knowing the root depth of the plants you want to grow can help you determine how extensively to prepare the soil.
If you install raised garden beds over concrete or gravel, you’ll want to know the root depth of the vegetables going in, since they will guide how high you need to build the sides of your beds.
Hydrozoning is the practice of grouping plants with similar water needs together in order to conserve moisture and irrigate more efficiently.
While we usually think of roots as growing downward, it’s important to remember that roots grow laterally as well, and to account for that in our garden beds and containers.