How and When to fertilize Azalea to get the best results

How and When to fertilize Azaleas to get the best results

Knowing when to fertilize Azalea is vital to getting the most out of your money, time, efforts, and plants. There are gardeners who refuse to feed their plants at all, while there are others who fertilize their plants excessively. This has a negative impact on the growth of Azaleas. So, in this essay, Garden How will go over some advice on how to fertilize Azalea properly.

When to fertilize Azalea

The best time to fertilize Azalea is after their spring blooms have faded. The majority of fertilizer applied before this bloom cycle won’t be absorbed. This is due to the fact that when the soil is cold, Azalea roots take in fewer water and nutrients. Additionally, fertilizing your plant with a balanced fertilizer in the early spring may stimulate it to flush out with new growth rather than concentrate on bloom development, which isn’t ideal.

They have a natural foliage flush cycle that occurs after the spring bloom, so fertilizing at this time will help to boost and improve this growth. It will grow faster and generate more foliage than it would if it didn’t have it. This is an excellent approach to ensure that your plant gets off to a good start in the growing season and that it receives the nutrients it requires to perform well throughout the year.

To keep your plants healthy, all you need to do is apply fertilizer once a year in the spring. However, let’s assume you’ve just received your plants, it’s late summer or fall, and you’d like to get them started in your landscaping.

If you have two or more months before the first forecasted freeze of the year, you can go ahead and fertilize Azalea using a slow-release balanced fertilizer. It be will able to create new growth that has time to harden off before being exposed to a hard freeze in this manner. The young foliage will die if it hasn’t hardened off by the time the first freeze occurs.

Use a rooting stimulant fertilizer if you have less than two months until the first forecasted freeze of the year. Instead of fresh leaves, this will urge your plant to create new roots.


How to fertilize Azalea?

1. Check your soil first

To avoid overfeeding, Jim Putnam, a consulting specialist for Encore Azalea and the founder of HortTube, recommends learning more about the quality of your soil before purchasing fertilizer. “A soil test will tell you what kind of nutrients your soil needs for your Azaleas to thrive – or whether you should fertilize Azalea at all,” he explains. “Once you’ve decided that fertilizing is the best course of action, make sure you use an Azalea-specific recipe.”

2. Choose an acidic fertilizer

According to Fidel Perez, horticultural manager at Bellagio Resort & Casino in Las Vegas, Azaleas grow in acidic soils, which provide the optimal habitat for nutrient absorption. “An acidic fertilizer will assist in maintaining the proper pH for the plant to absorb nutrients,” he explains. What is the significance of acid? Azaleas are major iron eaters, and iron is more easily available in lower pH (or acidic) soils, he explains. If the pH of your soil is between 4.5 and 6.5, it’s probably already acidic enough, and you can use a typical slow-release fertilizer that you’d use on other plants instead.

fertilize Azalea

3. Fertilize Azalea

Azaleas require small amounts of nitrogen (N), phosphorus (P), and potassium (K) for proper growth, as well as other trace elements.

A specialized fertilizer, such as Miracle-Gro Azalea (which comes in granular form), is the best way to fertilize Azalea since it includes the right combination of nutrients that Azaleas require at the optimal concentration.

Granular plant food is very simple to use. Simply add the granules to the soil around your Azaleas and cover them with mulch in the early spring, and the nutrients will be released into the soil as the soil temperature rises during the growing season.

Simply add the granules to the soil around your plants
Simply add the granules to the soil around your Azaleas

Because of the rate at which nitrogen (the nutrient that Azaleas require the most) is released, slow-release granules have an advantage over liquid-based fertilizers.

Because nitrogen is water-soluble, it is readily washed out of the soil after rain. In comparison to granular fertilizers, liquid fertilizers require more applications to maintain adequate nitrogen levels in the soil.

When non-specialized, general fertilizers are used, Azaleas are susceptible to leaf scorch at the tips owing to excess nitrogen, which can kill the plant if the nutrients are not properly concentrated.

Because young plants are especially susceptible to high nitrogen levels in the soil, it’s critical to utilize a precise fertilizer to eliminate the guesswork and risk of feeding your Azaleas.

In a nutshell, understanding how to fertilize Azalea is critical for producing the best flowers and a disease-resistant plant.

Azalea fertilizing tips

Because you don’t need to fertilize these bushes during the growing season, you don’t need to set up an Azalea fertilizing program. Only fertilize when the plants exhibit signs of requiring Azalea fertilizer. Never fertilize during a drought since the plant will be unable to get enough water.

You’ll probably need to fertilize Azalea if you use fresh sawdust or wood chips as mulch. The nitrogen in the soil is depleted as a result of the decomposition of such products.

Is fertilizer always necessary?

fertilize Azalea
Is fertilizer always necessary?

Because Azaleas aren’t heavy feeders, fertilizer isn’t always necessary.

Azaleas can develop to their full capacity and provide stunning flower displays without additional fertilizer if the soil has been modified before planting with well-draining compost.

If your Azaleas have dark green leaves, healthy development, and bloom in the summer, you’ve likely produced optimal soil conditions, and you’re unlikely to require fertilizer, as more feeding could cause more harm than good. 

Azaleas thrive in their native temperate regions of Europe, North America, and Asia as long as the soil is rich in organic matter, drains well, and maintains a moisture balance.

Yellow leaves or poor growth on your Azalea, on the other hand, could indicate a nitrogen deficiency in the soil. In this situation, treat the soil with nitrogen, and the Azalea leaves should recover to a healthy green within a few weeks.

If your garden soil is sandy and deficient in nutrients, or if the Azalea is competing for resources with trees or other plants in the area, a fertilizer application in the spring may be important to keep the plant healthy, disease-resistant, and looking its best.

In many circumstances, simply applying mulch to the soil would suffice, as it would provide nutrients, preserve moisture (Azaleas prefer damp soils), and improve the soil structure.

Mulch options for Azalea plants include compost, leaf mold, and well-rotted manure. Mulch is best applied in the spring because it progressively adds fertility to the soil while also slowing soil evaporation on hot, dry summer days.

Because store-bought compost used for potting and planting may not contain all of the necessary nutrients and trace elements (such as magnesium and iron) in minute quantities, adding slow-release fertilizer to Azaleas in pots and containers is advantageous.

The best fertilizer for Azaleas

If you want to give your Azaleas a boost and add fertilizer, we recommend choosing one that is acidic for Azaleas and rhododendrons. If Azalea fertilizer isn’t available, a well-balanced slow-release 10-10-10 fertilizer will suffice. Here are several fertilizers that we recommend.

  • Miracle-gro
  • Fertilome
  • Nelson Acid for Azalea
  • Jobe’s Azalea, Camellia & Rhododendron Fertilizer Spikes
Miracle-gro - fertilize Azalea
Miracle-gro – one of the best fertilizer for Azaleas

Questions and Answers

Can you fertilize Azalea while they’re blooming?

Because all Azaleas require the same basic nutrients, you would believe that the Azaleas variety has no bearing on when you fertilize your plants. Although not all Azalea varieties bloom at the same time, Azalea variation does have an impact. Fertilize Azalea in the spring, either during or just after blooming. It’s better to avoid fertilizing them right at the start of their bloom if you’re going to fertilize them. Instead of fertilizing as soon as the buds open, wait until the shrub has produced multiple blossoms. Azaleas can bloom anywhere between February and September, depending on the type.

Can you fertilize Azaleas while they're blooming?

How often should I fertilize Azalea?

Between flowering in the spring and bud set in the early fall, we suggest that you fertilize Azalea every 4-6 weeks during the growing season. You could use liquid fertilizers as a supplement, but for outdoor shrubs, we recommend a slow-release granular-based fertilizer.

Can you fertilize Azalea in the summer?

After mid-summer, avoid fertilizing because flower buds are starting to form, and feeding the Azalea will increase leaf growth at the expense of blooms.

The new growth will be more delicate and susceptible to frost. To be more resistant to colder temperatures, new season leaf development needs time to mature before winter. It’s much more vital to cease fertilizing Azaleas too late in the season if you live in a colder region.

You should not also fertilize Azalea in the fall and winter since nutrients will not be absorbed or the plant will develop when it should be preparing for dormancy.


In short, fertilize Azalea once in the spring with a continuous release of plant food for the best results. Fertilizer should not be used late in the growing season (after mid-summer), as this encourages new foliage growth, which is more susceptible to frost damage in the winter. Garden How hopes that these Azalea fertilization suggestions will assist you in growing breathtaking Azalea flowers.

Related posts:
Transplanting Azaleas into the garden – a new lease of life
4 Best methods for propagating Azaleas: Cutting, Rooting, Stem Layering and Air Layering
How big do Azaleas get? Factors affecting Azalea growth
When is the best time to prune Azaleas?

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