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).
By adding lime to your soil, your soil becomes more alkaline, and hence the color of your hydrangea can change from blue to varying degrees of pink. In general, 4 ounces of lime around the base of your hydrangea plant can change the pH of your soil by one point.