Connecticut Garden Journal: Rhododendrons
Early summer is still rhododendron and azalea time. There are late blooming, evergreen, large leafed varieties and native azalea species still putting on a show.
The large leafed rhododendron varieties, such the Catawba types, feature purple, white or red flowers on plants that can reach 6 to 8 feet tall. We've all seen these majestic rhododendrons around old houses. Some deciduous, native azalea species are good wildlife plants, and add splashes of color. These include the swamp azalea with white flowers and a pink tinge, and the plum leaf azalea with bright orange flowers. They bloom in June and July and grow best in a moist, shady, protected location in well drained soil. They're favorites of butterflies and hummingbirds.
The keys to successful rhododendrons and azaleas growing are afternoon shade, moist, well-drained soil, rich in organic matter and with a low pH. Evergreen rhododendrons benefit from winter protection so the leaves don't dry out. Wrap these with burlap, not touching the foliage, in early December.
Prune after flowering and propagate new shrubs by tip layering. This simple technique involves taking 1-year old, low lying branches, going back about 1 foot from the branch tip and removing leaves in that area. With a sharp knife, scrape off the outer bark on one side of the stem. Dab the wound with rooting hormone powder, cover with soil and secure with a tent stake or stone to hold the branch down. In 6 months to a year you'll have a new rooted plant you can cut from the mother plant and move to a new location.