Rhododendrons

Rhododendrons vs. Azaleas
Picking a Rhododendron
Growing Rhododendrons
Caring for Rhododendrons

“The poetry of the earth is never dead.”
– John Keats

Rhododendrons have been a favourite of gardeners across the globe for hundreds of years. It’s not hard to see why, either. With over 1000 known species of this gorgeous flowering shrub, there is truly a rhododendron for everyone!

Rhododendrons vs. Azaleas:

The names “Rhododendron” and “Azalea” have often been used interchangeably. Many people even believe they are the same thing! This isn’t all true, but it’s also not all wrong. While not all rhododendrons are azaleas, all azaleas are rhododendrons!

Azaleas are members of the rhododendron family, and are slightly different:

Stamens: Where Rhododendrons will usually have 10 or more stamens, azaleas
will always have 5.
Leaves: Azaleas have smaller, narrow pointed leaves. Rhododendrons leaves
are larger and more rounded, with a leathery texture.
Flowers: Rhododendrons will have bell-shaped flowers that grow in clusters.
Azaleas’ trumpet-shaped flowers usually grow on shoots (but sometimes in
clusters, too).
Winter Habit: Azaleas are usually deciduous, while rhododendrons are
evergreen.

Picking a Rhododendron:

Rhododendrons come in all colours and sizes across the world. From little shrubs that only grow a couple of feet, to varieties as tall as 25 feet, they truly have a wide range. Their pink and purple varieties might be the most famous, but they also come in dozens of other colours!

Rhododendrons are known for being low-maintenance in mild, temperate zones, preferring USDA Zones 4-8. Amongst their many species, though, there are a few hardy varieties that don’t mind Zone 3. The most hardy varieties will be easy to overwinter given the right planting and care, while more exotic varieties can make it with some extra TLC.

For best performance and sensational colour here in Edmonton, I recommend our pink Rosy Lights Azalea and purple  P.J.M. Rhododendron.

Growing Rhododendrons:

Rhododendrons are very picky about where they are grown, but won’t need much care if planted correctly. Like Goldilocks, they need their everything to be just right – not too little and not too much. Finding a location and conditions with the right sun and soil can be a challenge, but finding the right mix will reward you with tons of healthy blooms.

They absolutely need acidic soil to grow. If the soil’s pH is too high, the foliage will suffer from Chlorosis, turning the leaves yellow. Be sure to carefully monitor the soil’s pH before you plant or your rhododendron and provide care that keeps the soil pH in mind, or your plant simply won’t grow.

Rhododendrons also need evenly moist soil, but they hate having wet feet. The best way to get this balance right to fit your plant’s needs is by combining well-draining soil with a thin layer of bark mulch on the surface. The soil will drain properly, avoiding wet feet, but will have the remaining moisture locked in by the mulch to keep conditions more consistent.

With the right soil, your Rhododendron will also need just the right location to stay happy. They will do best in dappled sunlight, and sheltered from any wind that will rip their blooms to shreds.

Dig in with Alberta’s Best Gardening Blog for more information on your favourite garden plants!

Caring for Rhododendrons:

If planted properly, your rhododendrons likely won’t need much ongoing care. Keeping the soil evenly moist will be the biggest challenge. Luckily, mulch and the occasional rain will help. Water occasionally if it hasn’t rained much or if you notice the leaves beginning to curl. They aren’t big feeders, so a yearly dose of high-acid fertilizer will usually do.

Like most shrubs, rhododendrons love a yearly pruning haircut. Simply remove the dead buds carefully and trim away any leggy or dead growth. Since they bud on old growth, pruning is most effective if done right after the blooming season. Keep them sheltered from the cold, Alberta winter with a burlap wrap and watch your rhododendron dazzle year after year.

With one of the largest families in the flower world, rhododendrons have a stunner for every garden. Just because they aren’t native here doesn’t mean we don’t get to enjoy them, too. Plant them right and keep them comfortable and you can have radiant rhododendrons for many years to come!