How to Grow and Care for Rhododendrons
A Rhododendron bush, is a popular flowering bush and foundation plant, with
bright spring blooms. They are native to tropical and temperate regions.
While it is a bush, Rhododendron bushes can grow up to 80 feet tall!
Rhododendrons are closely related to Azaleas. The biggest difference between
the Rhododendron plant and an Azalea bush, and a
Rhododendron is an evergreen bush. (Note: There are a few varieties of deciduous
Rhododendrons, but they are not too popular with home owners) Generally speaking,
Rhododendron plants are larger in height, leaves, and blooms compared to
an Azalea. The Rhododendron also has a leathery type of leaf.
Propagation of Rhododendron:
Rhododendrons are grown from seeds, cuttings or grafting. Most home gardeners
do not start Rhododendrons from seed, as plant grown from seed takes 2-10
years to produce the first bloom. Most homeowners buy established Rhododendron
plants while in full bloom from a garden store. They transplant the Rhododendron
bush outdoors, after the booms have died off.
Planting and transplanting Rhododendrons is best done in the early spring
or early fall. When transplanting, replant bushes at the same level in the
ground was they were in their original location. Smaller bushes transplant
How to Grow Rhododendrons:
Rhododendrons are acid loving plants. They grow best in light shade, and
need protection from midday sun and winter sun. They prefer a moist, well
drained soil with a pH of 5.5.Check the soil pH before planting, especially
if planting along a foundation where soils tend to be more alkaline. Adjust
the pH, as needed. Mix in plenty of inorganic matter, and well
Selection of a location is important. Rhododendrons can be harmed or killed
by sustained winds and by too much direct sunlight. Select a location out
of the direct sunlight if possible. Protection from strong midday sun and
winter sunlight is important. Otherwise the leaves can dry out and/or burn.
Northern exposures are best. It is also important to provide protection from
winds. A low lying area, or one protected by a building or a hedgerow
is a good choice.
Rhododendrons prefer a moist soil. It is important to water the plants during
extended dry spells, even in the fall.
Using pine needles (acidic pH) as mulch works to help keep the soil moist,
and maintain/add acidity to the soil. Roots are shallow, so mulching will
help to keep the weeds down, without disturbing the root system.
Pruning or pinching back young plants will help to promote bushy growth.
Pruning should be done early in the spring. But any pruning may result in
cutting off next years blooms. If you prune an established bush heavily,
it may not bloom again for two to three years. At the thought of losing
next year's blooms, we recommend avoiding pruning established plants at all.
Just let them grow naturally however they want.
After a number of years, if the plant begins to grow too tall, major pruning
may be needed.
Winter Protection for Rhododendrons:
Rhododendrons can be harmed by winter burn, resulting from frozen soil, wind
and winter sun. As previously mentioned, selection of a location for your
Rhododendrons will help to avoid wind or sun damage. Some varieties are not
as tolerant to extreme cold. In northern areas of the country, ask the garden
store about the cold hardiness of the variety you are buying.
You can further protect your bushes by providing wind breaks that may double
to block some of the direct winter sunlight.
More on Winter Burn
Insects and Diseases Affecting Rhododendron:
Insect and disease problems are infrequent. Treat with insecticides or fungicides
only as needed.
Live Trees, bushes and Shrubs - hundreds of varieties
Also see: How to grow Azaleas