by Janet Harriett

Created on: April 01, 2008

As broad-leaf evergreen with a wide variety of flower colors, rhododendrons are a popular choice for the home landscape. Their four-season interest makes up for the extra care that must be taken selecting, planting and growing these colorful flowering shrubs.

Rhododendrons thrive in mild, humid climates; however, varieties exist that will grow in a range of climates. If you live in an area with cold winters or hot summers, selecting the right variety could mean the difference between a green, flower-filled shrub and a dead stick in the ground. While home improvement warehouses and garden centers will often stock rhododendron plants, the best bet for obtaining a plant that will survive in your climate is to get your plants from a local nursery that propagates its own stock, or to get a rooted cutting from a neighbor. For additional protection against winter damage in areas prone to sub-freezing temperatures, spray the rhododendron with Wilt-Pruf as winter is setting in. During an extended freeze, the rhododendron's leaves will continue to transpire moisture out, but the roots will be unable to take up additional moisture from the frozen ground, distressing the plant in much the same way under-watering does. Wilt-Pruf is an organic pine oil based spray that coats the broad leaves of the rhododendron to reduce this loss of moisture during times when the plant will be unable to replace lost water.

Rhododendrons prefer acidic soil, setting them apart from many other landscape shrubs, which tend to prefer neutral or slightly alkaline soils. While rhododendrons look great around a house's foundation, the soil there is not usually suited for rhododendrons, as construction debris and leeching minerals from the foundation tends to make the soil immediately around a house alkaline. Conditioning the soil in the area where the rhododendron is to be planted can compensate for this. When planting a new rhododendron, mix half sphagnum peat and half soil into the planting hole, mulch with pine needles or other acidifying mulch, and, when fertilization is necessary, feed with an acid-loving plant food or acidic fertilizer.

Like their close relatives the azalea, rhododendrons have a reputation as shade loving plants. This does not mean that rhododendrons should be planted in deep darkness where the sun never shines. They thrive in dappled shade and areas that get a few hours of morning sun. Behind evergreen windbreaks and on the east sides of structures are excellent spots for rhododendrons. The windbreaks or building will also shelter the rhododendron from winds. As shallow-rooted plants, rhododendrons will do best sheltered from high winds.

The shallow root system also means that care must be taken to keep a rhododendron's planting area free of weeds that will compete for water and nutrients. Hand pulling of weeds is best, to avoid potentially damaging the thin, shallow roots. Mulching thoroughly with an acidifying mulch will also help suppress weed growth in the immediate area.

Once a rhododendron is established, the care it requires is minimal. They are slow-growing plants that don't require much pruning, except to keep them down to the desired size. Annually renewing the mulch, keeping the weeds down, deadheading the spent flowers, and, where necessary, providing some winter protection to the plant should be all you need to do after the first year to be sure you can enjoy your rhododendron for years to come.

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