Growing climbing azaleas is just like growing an azalea bush, only you train the climbers onto a trellis or arbor. Azaleas are very similar to rhododendrons as they both grow in the same conditions. While it is not difficult to grow climbing azaleas, some care is needed when preparing their planting site. Many varieties of climbing azaleas are hardy between zones 5 to 9, so they will grow in warm to cold climates.
Choose a variety of climbing azalea that will grow well in your climate zone.
Choose a spot to plant your climbing azalea. Climbing azaleas grow best in partial shade, so plant on the east side of a building. Climbing azaleas also need rich, well-drained soil. If your soil is too clay-like, add sand and compost or manure to increase drainage. If you soil is too sandy, add compost or manure to increase the organic matter in it.
Test your soil's pH. Climbing azaleas like acidic soil with a pH between 6.0 to 5.5. If your soil is not acidic enough, add sulfur to increase the acidity. Add about one pound of sulfur per 30 square feet of soil.
Plant climbing azaleas in the spring after the last frost. Place the trellis you want the azaleas to climb behind the spot you want to plant them and secure it in the ground. Place it at an angle with the wall for maximum support.
Dig a hole for your climbing azaleas. Make sure the hole is about 1 to 2 feet deep and 3 to 4 feet wide, large enough to accommodate the root ball but not very deep. Place the climbing azalea in the hole and cover with soil, patting down firmly. Avoid covering the crown of the climbing azaleas with soil.
Attach the climbing azaleas to the trellis with the string. Tie three or four main branches to the trellis loosely. Once the climbing azalea wraps around the trellis the ties may be removed.
Water climbing azaleas regularly, about once a week for 5 minutes a watering.
Fertilize climbing azaleas in the spring with a mixture of 6-10-4. Apply 1 lb. per 50 square feet to the base of the climbing azaleas and water.
Prune climbing azaleas in the late spring or early summer, once they have finished blooming. Pluck off the dead blooms and remove any dead, damaged or diseased branches. No other pruning is needed.