Hydrangea care: soil pH and watering techniques for healthy blooms

Proper care for Hydrangea macrophylla involves managing soil acidity and hydration to maintain vibrant colors and prevent wilting. To achieve intense blue flowers, plants require acidic soil with a pH between 4.5 and 5.5. This acidity allows the plant to absorb aluminum, which reacts with the pigment delphinidin to produce blue hues. In neutral or calcareous soils, aluminum remains unavailable, causing the flowers to turn pink or red.

Ideal planting locations include semi-shaded areas with morning light and protection from afternoon sun, ideally near north or northwest-facing walls or hedges. To prevent flowers from browning during summer heat, deep watering is essential. For mature plants in the ground, providing 5 to 8 liters of water per plant two to three times a week is recommended. Watering should be done in the morning to avoid thermal shock to the roots caused by watering overheated soil in the late afternoon.