How often should I water hydrangeas?
Written by
Michael Sullivan
Reviewed by
Prof. Martin Thorne, Ph.D.The appropriate watering frequency determines the health, bloom quantity, and quality of hydrangeas. A consistent supply of moisture is always necessary. Still, while plants require consistent moisture, they do not need to live in soggy soil, which can lead to root issues and plant death. Deep watering encourages roots to grow down into the soil profile until they reach nutrients available in the soil. The different varieties have slightly different needs, but all require their soil to be monitored for drying out. My hydrangeas survive with deep watering once a week during typical growing weather.
Moisture Checking
- Test soil dryness by inserting finger 4 inches deep
- Water when soil feels dry at this depth
- Use moisture meters for accurate readings in root zones
Watering Technique
- Apply water slowly at soil level using soaker hoses
- Avoid wetting foliage to prevent fungal diseases
- Water until soil is moist 8-10 inches deep
Mulching Benefits
- Apply 3 inches of organic mulch around plants
- Retains moisture reducing watering frequency 30%
- Use bark chips or shredded leaves for best results
Container Watering
- Check pots daily during summer heat
- Water until excess drains from pot bottoms
- Use saucers but empty after 30 minutes
Soil composition has a considerable impact on the function of water retention. Sandy soil drains quickly, needing more frequent watering. Clay soil retains moisture longer, requiring less frequent watering. Amend plantings with compost to enhance the soil's moisture-holding capacity. My hydrangeas planted in clay soil only need to be watered half as often as those grown in sandy soil.
Extreme weather patterns will necessitate adjustments to your watering schedule. When the temperature is above 85°F (29°C) during a heatwave, water your plants early in the morning to minimize evaporation. Temporary shade cloth can be added during a heat wave. After heavy rain, do not water again until the soil has dried. In drought conditions, water deeply but with less frequency to promote deep roots.
Identify hydration signals evidenced in your plants. If leaves wilt during midday heat, this indicates a temporary state of stress - watering is not necessarily required. If they are still wilted when you wake up in the morning, that alerts you that watering is needed - now! Yellowing leaves are often associated with overwatering, while brown, crispy edges indicate that the plant is underwatered. You may need to adjust your watering schedule based on how your plants respond!
Water quality is important when caring for your plants. I recommend using rainwater when it's available. Tap water may contain small amounts of minerals that can affect the pH of your soil. If you opt to use tap water, allow it to sit overnight, which will allow the chlorine content to dissipate. Softened water is often treated and contains salt, which can have an adverse impact on your roots. I would also collect rainwater and fill it in barrels to use solely on my hydrangeas.
Consistent schedules help eliminate stress fluctuations: set aside specific days to water your plants, ensuring consistency, but adjust according to changing conditions. Watering in the morning allows the plant to absorb water before it evaporates. Watering in the evening warrants a higher risk of fungal disease. I always check the soil every Tuesday and Friday, watering if necessary.
Read the full article: How to Care for Hydrangea: Complete Growing Guide
