Soil Depth Requirements for Common Garden Vegetables
|Shallow Rooting 12" - 18"||Medium Rooting 18" - 24"||Deep Rooting 24" - 36"+|
Also question is, how deep does a planter box need to be for herbs?
Large bulbs require a planting depth of 8 inches, which means the planter box should allow for the 6 inches needed at the bottom, as discussed earlier, making the depth at least 14 inches. Most smaller bulbs are planted at 3 to 4 inches deep, so they would do fine in planter box with an 8-inch depth.
How deep does a planter need to be to grow tomatoes?
Tomatoes generally require a minimum of 10 inches of soil depth for proper root growth, but 12 inches is better for determinate and indeterminate varieties. Most indeterminate types also require some form of staking to support the vine, so it's best to choose a deep planter to anchor the support.