Watering Azaleas and Rhododendrons: Tap Water vs. Rain Water

Azaleas, rhododendrons, and camellias prefer acidic soil, but the idea that they require rainwater is a myth. Tap water is perfectly fine for most gardeners.

The Truth About Tap Water

While rainwater is naturally soft and slightly acidic, municipal tap water's dissolved solids (calcium, magnesium) are quickly leached from well-draining, organic-rich soil. Unless your water is extremely alkaline (high pH) and you have heavy clay, tap water won't harm these plants.

Best Practices

• Use an acidic fertilizer like Miracid or a dedicated azalea/rhododendron formula.
• Side-dress annually with peat moss or pine bark mulch to maintain acidity.
• Water deeply at soil level; avoid wetting foliage to reduce disease.
• Mulch 2–3 inches to conserve moisture and moderate soil temperature.

If you have a rain barrel, by all means use it—but don't stress if you don't.