Are Azaleas Considered Annual, Biennial, or Perennial Shrubs?
Thinking of planting azaleas but aren't sure if they will come back each year? Azaleas are beautiful flowering shrubs, and it's important to understand about their life cycle before you start planting. In this article, gardening expert Jill Drago examines if azaleas are classified as annual, biennial, or perennial shrubs!
When spring arrives our eyes are usually on the precious flowering spring bulbs that are emerging out of a frosty ground. It is easy to forget that there are many other plants out there that are just a few weeks away from their peak season. Azaleas are one of those plants. Their brightly colored flowers light up gardens throughout the spring and summer months and their green foliage will provide good privacy after the flowers fade.
Azaleas are stunners in the garden when they are planted correctly. These shrubs are known for their love of dappled shade and well draining soil. But will they keep coming back year after year, or will they fade after the growing season ends?
If you are curious how to work azaleas into your garden, you should learn a bit more about how they grow and what they might require from you. Read along to find out if azaleas are annuals, biennials or perennials.
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The Short Answer
Azaleas are perennial flowering shrubs. These beauties will return happily each spring after a winter of dormancy. Some azaleas drop their leaves in the winter, while others keep them throughout the coldest months of the year.
Differences in Plant Types
Annual
You may be familiar with annuals that are sold in 6 packs or 4 inch pots at your garden center in the summertime. They are typically brightly colored and a bit more showy. These plants only need one year to complete its life cycle, growing from a seed until it produces more seeds and then dies.
If you want to keep your annuals alive and produce flowers all summer and into the fall you will need to continue deadheading until the first frost hits. Examples of annual plants are geraniums and petunias.
Biennial
Biennials are plants that take two years to complete their life cycle. Frequently these plants will self seed and new plants will grow from those seeds giving the plant the illusion of being a perennial. Delphinium is a biennial.
Perennial
Perennials are in it for the long haul. These plants will live nice lengthy lives if they are planted in the right spot. There are many different care requirements for different types of perennials. Examples of perennials are black eyed susans, or salvia.
Evergreen vs. Deciduous
Plants that are considered evergreen do not lose their leaves or needles in the winter. These leaves also remain green all winter long. An example of an evergreen plant is a holly. Plants that are considered deciduous will lose their leaves at some point during the fall or winter.
There are also plants that are semi-evergreen. These types of plants may lose some of their leaves, but not all of them. Or they could lose all of their leaves for a very brief period of time before rejuvenating. Azaleas could be any of the above.
Where Are Azaleas Hardy?
You will find that most types of azalea are hardy in zones 5-9, however, some are not very cold tolerant at all. It is very important to do your homework on a specific variety before planting. If you plant a variety that doesn’t tolerate cold, you’ll spend more time reviving it from the dead than if you picked the right plant from the beginning.
Typically your local garden centers will only sell plants that are hardy in your area. While most plant labels do a good job of telling you exactly which climates are suitable for your plants, there are some microclimates that may not be perfect for all varieties.
Growing Perennial Azaleas
Azaleas tend to be extremely low maintenance plants that tend to take care of themselves. These flowering shrubs love acidic soil which could range anywhere from 5.5-6. You can find your soil pH by getting a soil test, or using a pH meter.
Azaleas also love soil that is well-draining. These shrubs are susceptible to root rot, and excess water in your soil will increase your chances of losing your plant.
Some varieties can tolerate full sun better than others. To be safe, most azaleas thrive when they are planted in partial shade. If you live in a warmer climate the shade will be crucial to the survival of the plant.
Plant your azaleas in the spring or fall when the temperatures are a bit cooler. Choose a site that is protected from the wind. This will help the plants retain more moisture, and help to prevent any transplant shock. Gently break up the root ball from the nursery pot and plant it in the ground, situating the rootball two inches above the existing soil line.
Azaleas are shallow-rooted plants, which means they can dry out quickly. Add some mulch to your gardens to help your soil retain some of that moisture. Similar to most shrubs, azaleas do best with one inch of water per week. Depending on your climate, you may need to hand water to make sure your azaleas are getting enough to drink.
Container Grown Azaleas
Azaleas are easy to grow in containers. This is a great option if you don’t have enough shade to keep your azaleas happy, or if you just want azaleas everywhere… including your patios and porches.
Growing azaleas in containers is the same as growing them in the ground, they need partial sun and well draining soil. Azaleas are toxic to pets and humans when ingested, so position these pots away from areas where kids or pets may be playing.
If you live in cooler climates where winter frosts and snow occur, you will want to bring your potted azaleas inside or into a sheltered location for the winter to protect the roots of the plant.
Popular Varieties
- Delaware Valley White will grow to 4 feet tall, with crisp white flowers.
- Encore Autumn Cheer is a dwarf variety reaching about 3 feet in height.
- Mandarin Lights will grow to 5 feet in height, with bright orange flowers.
- Mother’s Day will grow to about three feet tall, with bright pink flowers.
Annual Azalea Alternatives
If you love the look of azalea flowers and would like to keep the look going all through the summer, give some of these annuals a try. They might not be exact replicas, but they will get the job done!
Geranium
Geraniums can grow perennially in hardiness zones 9-10, but are treated as annuals everywhere else. They love full sun, but can be tolerant of some dappled shade.
Geraniums will bloom all season long if properly cared for. You can opt for bright pink geranium varieties such as ‘Robin’s Rose‘ or a bolder red variety such as ‘Patriot.’
Pansy
Pansies are considered short lived perennials in hardiness zones 6-10, but are typically treated as annuals in almost all climates. They can withstand the cold, but they do not like the heat.
They will perform the best in full sun to partial shade, and will bloom throughout the spring. It’s possible for pansies to bloom again in the fall if you keep them shaded through the summer. Look for varieties like ‘Sangria’ for an azalea-like look.
Superbells
Superbells can be grown as perennials in hardiness zones 9-10. They are treated as annuals in all other climates. When planted in full sun, they will be more apt to show off their beautiful blooms. They can survive in dappled shade, but this will impact their ability to flower.
Superbells flower through summer until the first hard frost. For varieties that look like azaleas, take a look at ‘Double Ruby’ for a hint of maroon color, or ‘Double Orchid’ for the frilly look that azaleas bring.
Final Thoughts
Adding these beautiful flowering shrubs to your perennial gardens will add season long interest, either with the brightly colored flowers, or the vivid green foliage. Flowering shrubs are often forgotten gems in the landscape with the allure of perennials and annuals but the investment in these plants will be long lasting. Happy planting!
