Root. In the computer world, root refers to the top-level directory of a file system. The word is derived from a tree root, since it represents the starting point of a hierarchical tree structure.
Use a fertilizer with high levels of phosphorus. Phosphorus helps to prevent aluminum from creeping into the system of the hydrangea. Choose a fertilizer close to the ratio of 25/10/10 (Phosphorus is the middle number).
Because too much phosphorus can harm your bones, it makes sense to eat less phosphorus. Some experts think 800 to 1,200 mg. of phosphorus per day is a good target. Food labels are not required to list phosphorus, so you will need to talk to a renal dietitian or find a nutrition reference guide and look up foods.