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).
Soil pH. Soil test results will help you determine the color of your hydrangea blooms. A soil pH of 5.5 or lower will produce blue flowers, and a pH of 6.5 or higher will produce pink flowers.Elemental sulfur gradually lowers soil pH and works best when incorporated into the top 6 inches of soil, while lime increases the pH.rganic Matter. To create rich, well-drained soil for your hydrangeas, add organic compost or aged manure to the soil. Organic matter provides food for beneficial soil microorganisms, which enrich and help aerate the soil. Well-drained soil provides room for hydrangea roots to grow and helps prevent root rot.