Are Hydrangeas Drought Tolerant?

Preferred Growing Conditions

• Two species of hydrangeas -- oakleaf hydrangea (H. quercifolia) and smooth hydrangea (H. arborescens) -- are native to the eastern U.S. Both grow wild in woodland areas. Oakleaf hydrangea grows in U.S. Department of Agriculture plant hardiness zones 5 through 9, while smooth hydrangea grows in USDA plant hardiness zones 4 through 9. Most other species commonly grown in the U.S. hail from Asia, where they are also found in woodlands. Keep this preferred growing environment in mind when planting hydrangeas. They thrive in partially shaded areas with moist, humus-rich soil. In hot, dry conditions, the plants fail to bloom, wilt and become sun bleached. In general, try to keep the soil consistently moist 1 inch beneath the surface.

Varieties and Age

• How much water hydrangeas need depends on the age of the plant, as well as the variety. A newly planted hydrangea shrub's roots can't access moisture from the soil effectively. These young shrubs need frequent watering. Once the roots become established and you notice new growth, the plants need slightly less moisture. Panicle hydrangea (H. paniculata), which thrives in USDA plant hardiness zones 3 through 8, is more adaptable than most hydrangeas. It can tolerate less moisture, more sunlight and more cold than any other variety.

Water Conservation Tips

• If you live in an area with drought restrictions, you might wonder if you can grow hydrangeas. Wise planting and care can help, but your hydrangea will still need regular watering to survive. First, amend the soil with compost and peat moss. These amendments improve drainage, but also keep the soil moist. Peat moss can hold up to 20 times its weight in water, making it an excellent amendment for dry, sandy soils. Soaker hoses or drip systems use water more effectively than overhead sprinklers. Watering this way also reduces the risk of diseases spread by wet leaves. Hydrangeas don't tolerate deep shade, but they grow best in partial shade. In hot, sunny areas, they'll need more water. A mulch of 3 to 4 inches of wood chips or shredded pine needles keeps the soil moist and cool, while reducing weed growth.

Watering Frequency

• How often you water depends on your climate, the variety planted and growing conditions. If your area gets weekly rainfall, you might not need to water hydrangeas at all. In dry climates, water at least two or three times per week. Sandy soils need more water than loam or clay because the water quickly leaches out of these soils. Stick your finger in the soil to test for moisture, rather than waiting for the plants to wilt or show other signs of water stress. You can also insert a commercial moisture meter in the soil, which will alert you to dry conditions. Water hydrangeas first thing in the morning when temperatures are cool.