Everything You Need To Know About Growing Azalea

Written by Joel SImon in Shrubs

Azaleas are an easy-to-care-for shrub with festivals throughout the U.S. that celebrates their blooms.

Azaleas are native to North America, Europe, and Asia where they grow as evergreens and deciduous shrubs.

They are related to rhododendrons with over 50 wild varieties and about 800 total varieties with most being hybrids.

There are two types of azaleas, evergreen and deciduous with the evergreens being smaller than the deciduous varieties.

Evergreen varieties are native to Asia whereas deciduous varieties are native to North America.

PLANTING AZALEAS

Azaleas are best planted in hardiness zones 5 through 9 in well-drained soil with full sun and a soil pH range of 4.5 through 6.0.

They are best planted about 3 feet apart for a border look or 4 to 5 feet apart for a more natural mounded look.

For best results, it is recommended to till some compost into the soil before planting which is known as amending the soil.

Amending the soil will provide nutrients and help the soil retain water which will help during the hot summer months.

USES

Azaleas are often used as hedging, borders, walking paths, woodland gardens, cottage gardens, rock gardens, planted in mass, and potting containers.

FERTILIZING AND WATERING

Azaleas are best fertilized with a balanced slow-release 10-10-10 fertilizer or a homemade liquid fertilizer.

Fertilizer should start in the early spring, stop before the blooms appear, and be added again in the fall.

Azaleas require about one inch of water every week and may need more during the hottest and driest summer months.

MULCHING

Mulching azaleas will help the soil retain water which will reduce the amount of time it takes to water them.

The thickness of the mulch is best between 1 and 2 inches deep for optimal water retention and the mulch will also help to prevent weeds from growing around your azaleas.

It is best to add new mulch every year as the older mulch breaks down.

BLOOMS

Southern Indian Azalea Flower

Azaleas produce an abundance of five-petaled blooms that appear in late March through May and they rebloom in mid-summer through the fall.

Their abundant blooms are available in yellow, orange, red, purple, pink, white, and bi-colored blooms that attract butterflies.

When their blooms become wilted you can remove them which will cause the plant to rebloom.

This is called deadheading and when the blooms are not able to go to seed, the plant will rebloom to produce seeds.

HOW TO PRUNE AZALEAS

Azaleas that have diseased or damaged stems from overwintering should be removed and any overgrown branches while leaving enough leaves on the stem.

They are best pruned back in the spring after the blooms have wilted and again in the fall and any heavy pruning should happen in late winter and early spring.

In the spring, if there is any dead or damaged growth then it should be removed.

Any stems that have wildly grown much higher than the rest of the plant which is known as leggy growth should also be removed.

Azaleas produce the following season’s blooms at the beginning of July therefore any further pruning will decrease the number of blooms for the next season.

PROPAGATING

If you want to grow your azaleas from a seed you can start with a cardboard seed starter to start it in.

Using soil that is well mixed with compost when temperatures reach about 75 degrees Fahrenheit, they would germinate in 2 to 4 weeks.

Propagating azaleas with the method of layering is a natural way to have more azaleas. This is done by finding a branch that is low to the ground.

Dig a trench that is about two inches deep under the branch and bury the branch in the trench.

To keep the branch in the soil you will need to place something heavy enough to keep the branch in the soil such as bricks or rocks.

After about one year the new shrub can be cut away from the parent shrub and transplanted.

Another option for propagating azaleas is through cuttings which is a faster method than using layers.

Cuttings should be removed in the spring and only new green growth should be used.

Before removing a cutting from a plant, make sure that there are at least three sets of leaves.

After removing the cutting dip the cut end into water then into root tone and plant the cutting in a container, garden, or landscaping. After the cutting has been planted it is a good idea to sprinkle some root tone on the soil.

Another option is to use a piece of paper towel, place the cut end on the paper towel, sprinkle some root tone on the cut end of the cutting, fold the bottom of the paper towel to the top, and wrap the rest of the paper towel around the stem of the cutting.

After planting the cutting give it some water and time. If you see that the cutting is looking wilted then the cutting will not root and you will have to start over.

PEST

Azaleas have many pests that feed on the plant which opens the shrub to plant viruses that affect nearby plants.

Therefore, dealing with the issue before the infestation reduces the amount of vegetation or kills the shrub.

  • Scale
  • Thrips
  • Lace bugs
  • Caterpillars
  • Leafminers
  • Whiteflies
  • Nematodes

DISEASES

Azaleas that are planted close together can develop mold and mildew issues during times of high humidity.

If this is the case then preventive measures may need to be taken.

To prevent this from happening make sure to plant them far enough apart to allow for proper airflow.

OVERWINTERING

Insulating your azaleas from the cold winter months may be required to protect the shrub from freezing with a layer of mulch that is 3 to 5 inches thick to protect the roots from the cold winter temperatures.

When adding mulch, leave a ring around the base of the shrub that is about one inch thick.

When temperatures drop below 25 degrees Fahrenheit shrubs may need to be covered with porous materials such as burlap or an old bed sheet.

Do not use plastic because it will hold in any moisture which will freeze and may damage the shrub.

VARIETIES

There are hundreds of varieties of azaleas with thousands of cultivars to choose from with many different parent varieties that are native to Western China.

Azaleas have been bred for hundreds of years with more varieties being developed every year and with the hybridization of azaleas, there are now varieties that can grow in northern climates.

DECIDUOUS VARIETIES

Deciduous varieties of azaleas are hardier in colder regions and they will lose their leaves during the fall season.

FIREBALL AZALEA

  • Shrub size – grows to about 6 feet tall and 5 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – shades of red and orange
  • Foliage – first appear as a bronze color and then turn green and is oval-shaped, when mature and during the fall they turn into hues of purplish red color
  • Deer resistant – no

LEMON LIGHTS AZALEA

Lemon lights azaleas are a hybrid variety that was created at the University of Minnesota.

  • Shrub size – grows to about 5 feet tall and 4 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – yellow blooms that appear in mid to late spring and rebloom in the early fall
  • Foliage – bright green narrow oval-shaped foliage that turns into shades of burgundy and purple in the fall.
  • Deer resistant – yes

HOMEBUSH AZALEA

Homebush azaleas have a sweet smell on warm days, they produce semi-double blooms, and they are resistant to mildew.

  • Shrub size – grows to about 6 feet tall and over 4 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – rose-pink blooms that appear in mid to late spring and rebloom in the early fall
  • Foliage – bright green narrow oval-shaped foliage that turns into shades of burgundy and purple in the fall.
  • Deer resistant – yes

GIBRALTAR AZALEA

  • Shrub size – grows to about 6 feet tall and over 5 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – orange blooms that appear in mid to late spring and rebloom in the early fall
  • Foliage – bright green narrow oval-shaped foliage that turns into shades of orange, red, and burgundy in the fall.
  • Deer resistant – yes

SEMI-EVERGREEN VARIETIES

Semi-evergreen varieties of azaleas will lose some of their leaves during the fall and fill back in during early spring.

SOUTHERN INDIAN AZALEA

Southern Indian Azaleas
  • Shrub size – grows to about 2 -3 feet tall and 2 -3 feet wide
  • Drought tolerant – yes
  • Blooming colors – red, purple, pink, and white blooms that appear in spring
  • Foliage – green narrow oval-shaped leaves that are about 3 inches long
  • Deer resistant – no

EVERGREEN VARIETIES

Evergreen varieties of azaleas thrive in warmer climates and they will keep their leaves all year long.

CASCADE AZALEA

  • Shrub size – grows to about 4 feet tall and 6 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – white blooms that appear in spring
  • Foliage – green narrow oval-shaped foliage that turns yellowish green in the fall
  • Deer resistant – no

CHINZAN AZALEA

Chinzan azaleas are a dwarf variety.

  • Shrub size – grows to about 3 feet tall and 3 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – pink blooms that appear in early spring and they rebloom from mid-summer and last into the fall
  • Foliage – green narrow oval-shaped foliage
  • Deer resistant – no

CONVERSATION PIECE AZALEA

  • Shrub size – grows to about 5 feet tall and 5 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – white, pink, and purple tri-colored blooms that appear in late spring and last into the fall
  • Foliage – green narrow oval-shaped foliage
  • Deer resistant – no

FLAME CREEPER AZALEA

Flame creeper azaleas are small rounded shrubs that are great for ground cover, rock gardens, walking paths, cottage gardens, borders, and containers.

  • Shrub size – grows to about 3 feet tall and 3 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – red blooms that appear in late spring and last into the fall
  • Foliage – green narrow oval-shaped foliage that transforms into a red hue in the fall
  • Deer resistant – no

HOT SHOT GIRARD AZALEA

Hot shot girard azalea is a small shrub that is great for ground cover, rock gardens, walking paths, cottage gardens, borders, and containers.

  • Shrub size – grows to about 3 feet tall and 3 feet wide
  • Drought tolerant – yes when established
  • Blooming colors – red blooms that appear in late spring and last into the fall
  • Foliage – green narrow oval-shaped foliage that transforms into an orangeish-red hue in the fall
  • Deer resistant – no

Joel SImon

As a kid, Joel found enjoyment in caring for the many houseplants he grew up with, learning how to transplant them safely, cloning them, and more. At about the age of 10, he wanted to see if he could sprout an orange seed from a store-bought orange and ended up using it as a science experiment in a school project. Throughout the many years of gardening, he has helped many friends and family set up their food and botanical gardens. After years of caring for plants, he was talking with other gardeners and discovering old methods of farming and botanical gardening. Joel has decided to share his knowledge for others to enjoy as he has for many years.

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