When Sir Joseph Hooker was collecting rhododendron seed in the Himalayas 150 years ago, he remarked that above 12,000 feet in Darjeeling, about three-quarters of all plants were rhododendrons. If Hooker were to walk through some neighborhoods in the Northwest or coastal Northern California today, he might make a similar observation―that three-fourths of all the flowering shrubs are rhodies. There's good reason for that. As landscape designer Beatrix Jones Farrand once noted, no other shrub compares with them for grand effect.
The photographs on the next 2 pages show some of the beautiful ways rhododendrons can be situated in various landscapes. The design challenges come in giving these bold evergreens enough shoulder room and keeping their flower colors from clashing.
As you choose among nursery plants in 2-gallon cans, remember that, with time, most will grow taller than you. So before you buy, ask the nursery staff about the plant's size at maturity.
Rhodies for small spaces
Even if you only have a small space, it's usually possible to work a plant or two into the garden.
LOW BORDERS. Lower-growing rhododendrons (to 3 feet or less) are the ones to use in short borders along entry gardens or paths. These compact rhodies tend to have smaller leaves.
LIVING SCULPTURES. Place a small, shapely rhododendron as you would place a sculpture in your garden―at the ends of paths or in locations framed by larger plants.
ESPALIERS. Fortunately, most rhododendrons take well to pruning, so you can train them almost flat against a wall or fence. When you shop, try to find plants with a fan shape rather that a bush shape, so you'll have a head start on the training process.
Rhodies for grander shows
TALL BORDERS. Broad pathways and winding grass corridors look especially inviting when they're lined with tall rhododendrons (to 6 feet or taller). Grow such rhodies in places where trees rise above or behind them to provide scale.
NEAR THE WATER. Mass rhododendrons on the far side of a pool or pond so their flowers will be reflected in the water, doubling their impact. Just make sure the rhododendrons are planted well above the waterline; otherwise, the roots will rot in the saturated soil.
IN THE WOODS. Most hybrid rhododendrons trace their lineage to plants of the open forest, which makes them natural choices for woodland gardens. In low-maintenance areas, you can use rhodies to create an evergreen cover that goes well with ferns, ocean spray, and other native woodland plants.
Consider color, texture, scent
COLORS. Choose rhododendrons as if you were assembling a wardrobe, thinking in terms of complementary and contrasting flower colors. If you buy plants in bloom, you'll be able to see how well a pink flower truss picks up the hue of a burgundy-leafed Japanese maple, for example. In mass plantings, group similar colors together (reds and pinks, for example), but keep clashing colors apart or grow white-flowered rhodies as buffers between them.
LEAF TEXTURES. Whether you're planting rhododendrons together or mixing them with other plants, contrast is the key. Play large leaves against small ones, round leaves against narrow ones. Or use the classic technique of playing broadleaf rhodies off a contrasting background of conifers, as shown above.
FRAGRANCE. Plant fragrant varieties of rhododendrons by entries and patios, where you can enjoy their scent up close. Some good ones include 'Dora Amateis', 'Fragrantissimum', R. fortunei, and R. luteum, a deciduous azalea.
For further reading
The best new book about designing with rhododendrons is Rhododendrons in the Landscape by Sonja Nelson (Timber Press, Portland, OR, 2000; $29.95; 800/327-5680 or www.timberpress.com). Fifty-two pages of color photographs provide convincing examples.