The azalea mucronatum, from the Ericaceae family, is scientifically known as the rhododendron mucronatum hybrid and commonly known as mucronatum hybrid azalea. The most common of this hybrid is called the Delaware Valley White. It's a semi-evergreen, white flowering shrub that is hardy in gardening zones 5 through 9. This hybrid azalea will grow between 6 to 10 feet tall and its abundance of small white flowers will attract hummingbirds and butterflies. Planting these azaleas correctly is the most difficult part of growing the plants because they are very low maintenance.
Choose a location that has partial sun. Dig a narrow hole 6 inches deep and fill with water. If the water does not drain within four hours, choose a new location or build a raised bed for the azalea. Azaleas require well-draining soil. Planting should be planned for spring.
Take a soil test once you've found a location fitting the azalea. The pH should be between 4.5 and 6. If it is too high, add powdered sulfur to the soil according to the manufacturer's direction to bring the pH down. All azaleas grow best in an acidic soil.
Dig a hole twice the diameter and 2 inches deeper than the container you purchased your azalea in, in the area of the treated soil. Add a few handfuls of compost to the dug out soil to enrich it and help it to drain better. Place 2 inches of the amended soil back into the planting hole.
Carefully remove the azalea from the container and gently rinse off some of the soil surrounding the roots. Place the shrub into the planting hole and back fill with soil around the roots. The azalea should be at the same level it was in the container. Hand tamp down tightly.
Water the plant thoroughly to help establish the roots. Keep the soil moist but not soggy throughout the growing season.
Place 2 to 3 inches of mulch around the plant but keep it at least 2 inches away from the trunk. The mulch will help to keep the roots cool in the summer, warm in the winter and help to retain moisture. Because the mulch will break down, layers will need to be added once a year.