Broadleaf evergreens, these shrubs that offer year-round interest in our gardens, need some care now. Water is the primary need for rhododendrons and azaleas in August. After more than six weeks of summer dry weather, these plants show stress. The welcome rain of the second week in August wasn't enough to saturate their roots. Many of them are native to regions such as the foggy lower slopes of the Himalayas or the eastern U.S. Smoky Mountains, where summer rain falls frequently and copiously.
Rhododendrons have fine roots that grow very close to the soil surface.
They can dry out fast under adverse conditions. Use soaker hoses or in-ground drip systems if possible for watering. Rhododendrons and azaleas require deep, slow soaking that penetrates through the entire root ball. A wave of the hose for a minute or two won't do it, even if the surface of the soil looks satisfactorily damp. Take a trowel and check gently around the root ball to see how far the water has penetrated.