Azalea (Rhododendron simsii) Indoor Care: Cool, Bright, and Moist

Florist azaleas (Rhododendron simsii, often sold as Azalea indica) are prized for their masses of ruffled flowers in red, pink, white, and purple. But they're not typical houseplants—they demand cool temperatures, high humidity, and careful watering. Meet their needs, and they'll bloom for weeks in winter and spring when little else flowers indoors.

Temperature: Cool Is Critical

Day: 68–77°F (20–25°C). Night: 60–64°F (16–18°C). Never above 77°F. Warm rooms cause bud drop and leaf yellowing. In summer, move the pot outdoors to a shaded, sheltered spot—bury the pot in soil to keep roots cool.

Light

Bright, indirect light. No direct sun, which scorches leaves. A north or east window is ideal. Long days promote vegetative growth; shorter days (fall/winter) trigger flowering.

Water: The #1 Killer

Azaleas hate tap water—alkalinity and salts cause yellow spots and stunted growth. Use rainwater, distilled, or boiled-and-cooled water at room temperature. Keep the soil constantly moist but not soggy. Never let it dry out. Water from the bottom or submerge the pot briefly; avoid wetting foliage. Empty saucers promptly.

Humidity

High humidity is non-negotiable. Mist daily with soft water, use a pebble tray, or run a humidifier. Dry air = crispy leaf edges and bud blast.

Soil and Feeding

Acidic, organic-rich mix with high water retention (peat-based, pH 4.5–5.5). During bloom, feed every two weeks with a dilute, acid-forming fertilizer (e.g., for rhododendrons). Stop after flowering.

Post-Bloom and Repotting

After flowers fade, prune lightly to shape. Repot annually in spring (only if root-bound) into fresh acidic mix. With consistent cool, moist care, azaleas rebloom reliably each year.