Plant field guide
Azalea (Delaware Valley White)
One of the most cold-hardy white azaleas, covered in large pure white flowers in spring. Compact, dense evergreen habit. A go-to choice for foundation plantings and formal gardens in cooler climates.
Growing requirements
- Scientific name
- Rhododendron 'Delaware Valley White'
- Sun
- partial shade
- Water
- moderate
- Height
- 36 in (91 cm) – 48 in (122 cm)
- Spread
- 36 in (91 cm) – 48 in (122 cm)
- Spacing
- Not recorded
- Hardiness zones & minimum temperature
- USDA 5–8; average annual extreme minimum from -20°F (-28.9°C). Hardiness does not predict local frost dates.
- Difficulty
- easy
Planting & seasonal timing
Northern Hemisphere planting months: not yet verified in our database.
Northern Hemisphere pruning months: May, June.
For the Southern Hemisphere, these seasonal windows shift approximately six months. Check your local frost forecast, soil temperature, and species requirements; calendar months are not a guarantee of planting safety.
Exceptionally cold hardy for an evergreen azalea. Dense habit rarely needs pruning. Excellent disease resistance. Outstanding in mass plantings for a clean white spring display.
Pruning
Prune after flowering. Naturally compact habit. Light shaping only.
Fertilizer
Azalea/Rhododendron fertilizer (acidic)
After flowering
Mulch
2-3 inches of pine bark or pine straw.