Azalea Fertilizer: Tips For Feeding Azalea Plants

The Azalea flower is one of the most common spring blooms. It is beloved by people with a penchant for gardening. Lined along garden borders or in flower beds, azaleas make an excellent addition to any garden.

They are some of the most iconic shrubs you will see everywhere in the South. However, people in other areas around the States also enjoy their beauty.

Blooming Azalea with lots of flowersPin

Classified in the genus Rhododendron and part of the Ericaceae family, there are numerous species, varieties, and cultivars to use around your yard.

They hail from the Orient but are found around across the countries and are hardy to USDA zones 4 to 8.


Every year, they produce an abundance of beautiful blooms every early spring. Even to the untrained eye of an amateur gardener, azalea shrubs look spectacular.

The azalea flowers and lush foliage have been selectively bred for hundreds of years. Compared to other flowering shrubs, azaleas are relatively not hungry plants.

In fact, fertilizing might not be necessary for some varieties unless they show evident signs of malnourishment.

It is crucial you know when and when not to fertilize azaleas. If you see signs of nutrient deficiencies, using the right type of fertilizer in the proper way is important.

It will encourage good development, healthy growth, and vigorous flowering every growing season.

Also, you must also pay close attention to other growing conditions. This includes the soil, sun exposure, and planting location. More on planting Azalea bushes here.

Best Fertilizer for Azaleas

As mentioned previously, azaleas are not particularly needy when it comes to fertilizing.

You may not even need to add any fertilizer if you work organic matter or dried leaves into the soil.

This will provide most of the nutrients the plant requires to thrive.

If you notice the yellowing of leaves, stunted or reduced new growth, smaller leaves, or drooping, azalea fertilizer may help.



If you notice darker than normal leaves with dead tips, the plant might have a phosphorus deficiency.

However, these symptoms may be caused by other factors such as compacted soil.

It is better you get the soil around your azalea plants tested.

The soil test will determine whether the culprit is deficient soil or not.

If the test identifies a lack of nutrients as the cause, fertilizer will help.

The test will also determine what type of fertilizer your azalea plants need.

Typically, a high-quality balanced fertilizer e.g. 15-15-15 blend of NPK (Nitrogen, Phosphorus, and Potassium) will work fine.

In most cases, nitrogen deficiency in the soil is to blame for stunted growth.

This requires a high nitrogen fertilizer.

A water-soluble fertilizer like Miracle-Gro works well for azaleas, Camellia, and Rhododendron.

Related: Growing and Care of Rhododendron Plants

When and How to Fertilize Azaleas

How to Fertilize Azaleas

Before you begin feeding your azaleas and accidentally add too much fertilizer, wait for the soil test results.

Once they are in, select a basic balanced fertilizer. The basic idea while feeding azaleas is to get the fertilizer absorbed in the root system.

This means you have to spread the fertilizer evenly over the root system, which typically extends beyond the canopy of the azalea bush.

In fact, it can extend three times as far from the trunk to the branch tips.

If this distance is approximately 3′ feet, you have to fertilize 9′ feet from the trunk.

Make a circle on the soil with the trunk of the azalea in the center.

Sprinkle the slow-release fertilizer grains in the sketched area and then water well.

Make sure to wash off any fertilizer on the foliage.

When to Fertilize Azaleas

When it comes to the “when” of fertilizing azaleas, there is no schedule.

Having low nutrient needs and not requiring frequent feeding, you don’t have to fertilize all through the growing season.

Fertilize only when you see signs of a deficiency and only once.

However, you may need to fertilize again if you mulch your azaleas with wood chips or sawdust.

This is because they are organic materials and use up nitrogen as they decompose.

Also, avoid fertilizing the plants when there is a drought. Lack of water may have negative impacts on the plant’s growth.

With proper care and careful fertilization, it’s possible to bring your azalea back to life.

When the season comes, you will be able to see new flower buds emerge next year.