The doctor is in! Bush Doctor Cal-Mag by FoxFarm stops calcium deficiencies right in their tracks. As overlooked as calcium and magnesium are, a deficiency of these two nutrients can have a severe impact on your garden. The calcium and magnesium found in Bush Doctor Cal-Mag help strengthen cell walls while also preventing blossom root or tip burn. Bush Doctor Cal-Mag is OMRI-Listed and CDFA-registered for organic gardening.