Kingdom, phylum, class, order, family, genus, species.
This may sound like something you remember from your 7th grade Science class that you never thought you would hear again, but we are going to put it to use right now.
This is known as the taxonomy of a biological organism, also known as its classification rank.
Many plants or animals share the same taxonomy properties until reaching the family or genus classification. For example, dogs and cats are two very different types of animals, but they share all of the same classifications until reaching the family rank.
The family classification of domestic dogs is canine, where the family classification of domestic cats is feline. Dogs and cats are then each classified by genus and then finally species.
The same taxonomy classification applies to plants.
The genus of a plant contains a variety of different species, which brings us to rhododendrons and azaleas.
The Rhododendron Genus
Azaleas and rhododendrons have the same kingdom, phylum, class, order, and family. Both are in the Plantae kingdom and share the same classifications all the way down to the Ericaceae family. The Ericaceae family of plants are flowering plants that contain over 4,000 species, making it one of the largest families of plants in the world.
Rhododendron is the genus that is assigned to azalea species. Azalea is just one out of the 1,024 different species that are found under the rhododendron genus. This means that all azaleas are rhododendrons, but not all rhododendrons are azaleas.
If you were to go to a nursery and asked a specialist for a rhododendron, they would likely respond by asking which species you want. You may be looking for hybrids or particular varieties, like the vireya rhododendrons for instance. Rhododendrons contain over 1,000 different species of flowering bushes, shrubs, and small trees, many of which are the azalea.
The Azalea Species
Azaleas are a species of rhododendron, and there are thousands of types of azaleas to choose from. Azaleas are a rhododendron shrub that only grows a few feet tall and has smaller branches than some of the flowering tree species of rhododendron.
Azalea flowers bloom in a variety of colors and shapes. Some types of azaleas can survive in colder climates, while others do best in warmer zones.
Because azaleas are rhododendrons, they can be pruned, trimmed, and planted following the same guidelines as rhododendrons. Rhododendrons should be pruned when the plant is dormant, as this will cause the energy of the rhododendron to focus on the areas that have just been pruned.
The main difference in pruning azaleas from rhododendrons is that you should immediately trim off the dead and faded flowers are soon as they appear. Azaleas bloom in spring, anywhere from March to May, depending on the region in which they are planted, so flowers can begin to fade as early as late May or early June.
Azaleas will begin to produce new blooms in July, so you must trim all faded blooms before new blooms are present. Trimming faded blooms after new blooms have begun to grow will cause the azalea to produce significantly fewer blooms next year, which is the opposite effect you will want the azalea to have when pruning.
It is important to remember that azaleas are a species of rhododendron. While the difference between rhododendrons and azaleas is not huge, they share similar characteristics and can be cared for in similar ways, azaleas will thrive if they are pruned and trimmed according to their precise species.