The Spruce / Evgeniya Vlasova
Is it a rhododendron or an azalea?
It can be puzzling because all azaleas are rhododendrons, but not all rhododendrons are azaleas.
Both plants are woody, rounded shrubs in theEricaceae(blueberry) family with many cultivars and varieties.
The Spruce / Evgeniya Vlasova
Growing requirements, depending on the cultivar, for rhododendrons and azaleas are the same.
What Are Azaleas?
Native North American azaleas are deciduous, meaning they shed their leaves in the fall.
Height can range from under a foot to well over 15 feet.
Azaleas are relatively pest-free andare easy to grow.
Organic matter worked into the soil before planting will usually provide sufficient nutrients for adequate growth.
Yellowing leaves show a lack of iron which is essential for healthy azaleas.
system of an iron solution as a foliage spray should be applied during the growing season.
Types of Azaleas
What Are Rhododendrons?
Rhododendrons are small trees in theEricaceae familywith large clusters of bell-shaped flowers and large evergreen leaves.
Some varieties are compact while others resemble trees.
Sizes range from five to 20 feet or more.
Rhododendrons are native to North America, Asia, and Europe and there are thousands of hybrids.
The leaves are deep green elliptic, thick, leathery, and glossy.
The undersides may be scaly or have small raised dots.
As shallow-rooted plants, they require irrigation during dry periods.
This can be aided by mulching the plant at least four inches deep to help preserve moisture.
Disbudding is done on new growth and can be done again in the fall.
A few common insect problems arelace bugs, mites, andscale.
Some are dense and rounded, while others are open and upright.
Mature growth can range from under a foot to well over 15 feet.
Rhododendron varieties range from small hybrids to large tree forms that reach heights of five to 20 feet.
The back side of the leaves is smooth.
Rhododendrons are typically evergreen with deep green, thick leaves that are leathery and glossy.
The undersides may feel slightly fuzzy, scaly, or have small raised dots.
Flower Characteristics
Azalea blooms are funnel-shaped with five stamens.
The hybrid Encore azaleas bloom in the spring and rebloom in the summer and fall.
Rhododendron flowers are larger, bell-shaped, and have 10 stamens.
Most varieties bloom in June with the flowers appearing as clusters at the end of the branch.
Rhododendron blooms are typically white, pink, purple, and red.
Optimum growth and flower production will happen in well-draining, acidic (4.5 to 6.0 pH) soil.
Both plants should be mulched well to help keep the roots cool.
Rhododendron or Azalea?University of Washington.
Azalea Basics.Azalea Society of America.
