Is Azalea A Perennial Or Annual?

Written by Becky Mathews
Published: August 31, 2022
Image Credit PatGallery/Shutterstock.com
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Azaleas are truly beautiful shrubs with an array of vivid colors. They are grown worldwide for their stunning flower displays, but are azaleas perennials or annuals? Can they survive the winter, and how do you look after them?

Let’s find out more about azaleas and discover why Georgia designated azaleas their official state wildflower.

Azalea: Annual or Perennial?

azalea
Azaleas are evergreen or deciduous woody shrubs that flower every spring.

Ole Schoener/Shutterstock.com

Azaleas are woody shrubs, so they’re not actually annual or perennial! They don’t die back and re-emerge in spring, but some are deciduous (which means they lose their leaves in winter). This makes them more like perennials than annuals.

What’s The Difference Between Annual and Perennial?

Annual plants germinate, grow flowers and seeds, and die all within one year. Perennials live longer. They die back in the cold months to a root ball in order to survive frost, wind, rain, and snow. When temperatures rise, they re-grow.

Biennial plants grow for two years. They germinate in the first year, then complete their lifecycle of flowering and setting seed in the second year before dying.

Woody shrubs like azaleas flower each year, but they don’t die back. Their woody framework and foliage stay put during winter.

All About Azaleas

azalea
Azaleas are native to North America, Asia, and Southern Europe.

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Azaleas are part of the Ericaceae family in the rhododendron genus. There are evergreen shrubs called tsutsuiji, or pentanthera if they’re deciduous.

These plants are flowering woodland shrubs that like the shelter of trees and prefer partial shade. They are one of the plants that like acidic soil in the 4.5 -6 ph range. They also don’t grow well on chalk. If you try, the leaves will turn yellow (called chlorosis) and drop off.

Azaleas are native to Asia, Europe, and North America. The flowers emerge in spring, and because botanists have crossed the species so many times, there are hundreds of cultivars. Experts have recorded over 10,000 individual cultivars and their bloom range from white, yellow, red, pink, orange, blue, and purple.  

Slow-growing azaleas are planted as ornamental shrubs in private gardens, and there are lots of azalea gardens open to the public. In the States, Magnolia Gardens in Charleston opens from late March to April to show off their azalea collection. In southern England, Abbotsbury Sub-Tropical Gardens’ ‘Azalea Walk’ has blazed with azaleas since the 1700s, and Korea has a royal azalea festival every May.  

Different Species of Azalea

North American azaleas are five-petalled and deciduous. They have two different types of buds. One produces around 20 flowers, while the other matures into a leaf shoot.  

Fifteen different species grow across every state. For example, from Alabama to Pennsylvania, you will find a five-foot-tall white azalea called Rhododendron arborescens, and Rhododendron atlanticum is a coastal dwarf azalea that grows from Delaware to Georgia.

Asiatic azaleas are sometimes called Japanese azaleas or azalea Japonica. They are usually evergreen and shorter at around three feet. European azaleas, such as the yellow rhododendron luteum, are native to Southeastern Europe and are deciduous after a rich display of fall color.

In 1979 Georgia state selected azalea as its state wildflower and amended this in 2013 to specify native azalea.

Are Azaleas Easy To Grow?

Azaleas are easy to grow if you give them what they need. The two basic conditions azaleas need to thrive are shade and neutral to acidic soils.

If you have alkaline soil (that’s the chalky type), it’s best to grow azalea in a container of ericaceous compost.

Water them well until new growth appears, and apply a thick layer of well-rotted acidic organic mulch to the roots in early spring.

Do Azaleas Come Back Every Year?

Azaleas flower every springtime, whether they are evergreen or deciduous. Deciduous azalea’s foliage begins to grow back in early spring.

Should You Deadhead Azaleas?

It doesn’t matter if you deadhead azaleas because it doesn’t encourage any more flowers. Deadheading does make the shrub look tidier, though!

Will Azaleas Grow In  A Pot?

azalea
Azaleas prefer acidic soil or a container of ericaceous compost. They become chlorotic in alkaline soil.

Svetlana Mahovskaya/Shutterstock.com

Yes, azaleas will grow in a pot. In fact, it’s preferable if the yard soil is alkaline.

Pot-grown azaleas need lots of water in the hot months. The buds will drop off if they experience drought, and that means no flowers! This is because azaleas form their buds at the end of the growing season, ready for the following spring.

Can Azaleas Survive A Freeze?

Azaleas can survive sub-zero temperatures if they are grown in well-drained soil, but they do best in warmer climates such as the Southeastern States and the Pacific Northwest.

We already know that azaleas form their buds in late summer to fall. If frost and snow damage these buds overwinter, no flowers will bloom in spring. Use horticultural fleece to protect azalea buds in cooler areas.

Do You Cut Back Azaleas?

Pruning azaleas replenish the wood. Cut them back after the flowers are spent. This gives the shrub enough time to develop the following year’s flower buds.

Remove about 1/3 of each branch to maintain its size and cut out any damaged or crossed branches too. Water and fertilize after cutting them back to help azaleas put on new healthy growth. Use a specialist azalea feed, though – standard tomato feed isn’t acidic enough.

Is Azalea Poisonous To Pets?

Azaleas contain a neurotoxin called grayanotoxin. All parts of the shrub are toxic to pets and can cause death if eaten in large quantities. Symptoms of azalea poisoning are vomiting, difficulty breathing, depression, and coma.

What Is The Lifespan Of Azaleas?

Azaleas can live for decades, even up to 50 years, in the right conditions. They are very long-lived plants and a great investment if you’re starting out a garden.

Azaleas Are Neither Perennial Nor Annual!

azalea
Azaleas are neither perennial nor annual, but because they flower each year, some people call them perennials.

PatGallery/Shutterstock.com

Azaleas are woody shrubs that don’t die back. This means they are neither perennial nor annual, but because they flower each year, some people call them perennials.

Fun Facts About Azaleas

  • Azaleas are the national flower of Nepal.
  • Azaleas represent womanhood, but each color has a specific meaning.

Red: Romance

Pink: Femininity

White: Healing

Yellow: Friendship

Orange: Passion

Any color azalea in a black vase: Death Threat

  • The name azalea is Greek for ‘dry.’
  • Historically in southern Europe, bees were fed azalea nectar. The compounds in azalea are toxic, and this created ‘mad honey’ that was consumed as a hallucinogenic.

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About the Author

I’ve been a professional writer since 2014 with special interests in the environment, particularly endangered animal and plant species. I graduated from the University of Reading, UK with an MA in history and hold University of Oxford qualifications in archaeology. Outside of work, I rehabilitate wildlife, work in my allotment garden, and play the piano badly.

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Sources
  1. RHS, Available here: https://www.rhs.org.uk/plants/rhododendron/growing-guide
  2. Azalea Society of America, Available here: https://www.azaleas.org/
  3. ASPCA, Available here: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/azalea
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