Hardiest Azaleas and Rhododendrons

Growing Azalea and Rhododendron

Remember that the ability to grow Azaleas and Rhododendrons successfully depends also on the site selection and soil preparation.

• Their soil should be acidic, organic, moist, fertile, and well-drained.
• Choose a site with dappled shade in sheltered conditions. Avoid deep shade beneath other trees. Most Rhododendrons will tolerate a more open site if sheltered from cold, dry winds. Dwarf alpine species will tolerate full sun provided the soil is kept evenly moist.
• Many Azaleas and Rhododendrons are fully cold-hardy. However, a few of them have frost-resistant flowers. Any flowers blooming before the last spring frost are susceptible to damage. Since frost damage is generally caused when the early morning sun strikes the plants’ frozen tissues, you should site your Azalea or Rhododendron where both leaves and flowers are protected from the early morning sun and where they will adapt slowly to the increasing temperatures of the day. Since frost flows downward, avoid planting them in low-lying spots known as frost pockets.

• When placing plants, always choose locations that mitigate extreme temperature changes, especially in spring and fall, and protect from drying summer or winter winds. Azaleas and Rhododendrons may be harmed in winter by frozen grounds and drying winds or bright sun, which will cause severe foliage desiccation. Protect their shallow roots with a mulch of oak leaves or pine needles and their foliage with woven material such as burlap screens. This will help prevent bark-split (when the sap running in the stem is frozen and bursts the bark).