The vigorous blooms of hydrangea can change colors, depending on the acidity of the soil.
Water Requirements: Moderate water needs. Keep hydrangeas well-watered, but not soggy.
Light Requirements: Hydrangeas can handle a range of light, but part shade conditions with afternoon shade is best. This allows hydrangeas to get optimal light but stay out of the afternoon heat.
Soil: Well-draining, fertile soil. Generally, acidic soil will produce blue flowers, and alkaline soils will produce pink blooms.
Growth Rate: Fast. About 2 feet of growth per year.
Bloom Time: Summer to Fall
Temperature: Prefer shade when it is hot.
Pruning: Minimal pruning is needed. If size is an issue, older stems can be cut back.
Toxicity: Toxic to people and animals.
Tips: Add vinegar or coffee grounds to make the soil more acidic, which will make the blooms blue. Add phosphorous or garden lime to make the soil more alkaline, resulting in pink blooms.