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).
Since the discovery of their excellent anti-wear and fire resistance properties in the 1940s, the use of phosphate esters by industry has steadily increased. Phosphate esters are used primarily as fire-resistant basestocks in several applications including hydraulic systems, turbines and compressors.