Azaleas Need Water

Azaleas and rhododendrons that bloomed beautifully in May can still disappoint the following spring, and late summer dryness is usually the reason. According to Gardening Know How, a weekly soak from now through autumn protects the buds forming for next year.

Late Summer Care

Azaleas and rhododendrons look after themselves for much of the year, but late summer is a critical period. What happens to these shrubs in August and September rarely shows at the time, and the consequences arrive eight or nine months later as a sparse, patchy flush of flowers. Both azaleas and rhododendrons set next spring's flower buds during July and August, and watering them during this window is crucial.

Watering Requirements

The amount of water and frequency of watering are important. Aim at roughly 1 inch (2.5cm) a week, rainfall included. A rain gauge can help determine if supplementary watering is necessary. One long soak beats several short ones, and the soil should be wet down to roughly 8 to 10 inches (20-25cm). Shrubs in their first two seasons need closer attention.

Watering Techniques

The location of watering is also important. Both plants have a shallow fibrous root mat, confined almost entirely to the top 6 to 12 inches (15-30cm) of soil. Water should be poured around the drip line and slightly past it. A soaker hose laid in a loose ring around the shrub can handle the whole job unattended. Morning is the better time to water, as foliage dries before evening, which keeps fungal trouble off evergreen leaves.

Mulching and Drainage

Mulch can help hold moisture in the root zone and cool the soil underneath. A 2 to 3 inch (5-8cm) layer of pine bark mulch can be effective. However, too much water can be harmful, and ground that stays waterlogged can set up Phytophthora root rot. It is essential to check the soil moisture before watering and to ensure good drainage. A bed raised 12 inches (30cm) or more above grade can sidestep drainage problems entirely. As Tyler, a gardening expert, notes, these are low-effort tasks that can be spread out between now and the first hard frost, and keeping them up can result in a beautiful display of blooms next spring.