Spectacular shrubs with dramatic foliage and stunning flowers, azaleas (Rhododendrons spp.) are available in both evergreen and deciduous species and a huge range of sizes and colors. Although hardiness depends on the cultivar, most grow in U.S. Department of Agriculture plant hardiness zones 5 through 8. Propagate evergreen azaleas by taking cuttings from early summer until autumn. Deciduous azaleas root best from tender growth in late spring or early summer.
Fill a celled planting tray with a well-draining potting mixture such as a combination of half perlite and half peat moss. Mix 1/2 teaspoon of an all-purpose, dry garden fertilizer into each quart of potting mix.
Cut 2- to 5-inch stem tips from a healthy azalea. Cuttings taken early in the morning are most likely to root because the stems are plump and well hydrated. Use sharp, clean pruners to cut the stems just below a bud or leaf. Leave two leaves at the top of each cutting and remove any other leaves.
Scratch a small area of bark on the bottom of each cutting, using your thumbnail or the tip of a knife. The small wound helps the plant absorb hormones, water and nutrients.
Push your fingertip into the center of each cell to make a planting hole. Dip the bottom of the cuttings in powdered or liquid rooting hormone and then insert the cuttings carefully into the holes. Water the potting mix slowly to settle the mix around the stems. The potting mix should be evenly moist but not soggy.
Slide the celled tray into a clear plastic bag and close the bag tightly with a rubber band. Place a plastic straw or similar object in each corner of the tray to prevent the plastic from touching the potting mix or cuttings.
Place the tray in indirect light. Open the plastic for 10 minutes twice weekly to provide ventilation.
Remove the plastic covering and transplant each cutting into a 3-inch pot filled with regular commercial potting soil when the cuttings show healthy new growth, which usually requires about two months. Move the young plants into bright light and water regularly to keep the potting mix consistently moist.
Pinch the growing tip of each plant to encourage branching. Plant the young azaleas in 1-gallon pots in spring and then let the shrubs mature for an additional year before planting them in the garden.