This extension white paper puts a minimum of 18"-24", but also strongly advised that 24" is recommended.
This extension says 24"-36", with a strong emphasis on 36" for best results.
The USDA literally has 24" as a minimum.
Need more?
This extension white paper puts a minimum of 18"-24", but also strongly advised that 24" is recommended.
This extension says 24"-36", with a strong emphasis on 36" for best results.
The USDA literally has 24" as a minimum.
Need more?