Do Azaleas Need Ericaceous Compost?

Do Azaleas Need Ericaceous Compost

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Gardens are beautiful, and during the recent pandemic, many people turned to them for a chance for fresh air and something to do to ease lockdown boredom. Azaleas are one of the most popular flowering shrubs out there, but can you use the same compost with azaleas as with your other plants? Can you use on-site compost, like yard trimmings or leftover foods, or do you really need ericaceous compost?

Azaleas thrive in neutral to acidic soil that is rich in humus. While run-of-the-mill compost is okay to use with azaleas, it is highly recommended that you use peat-free ericaceous compost, as this is a more acidic compost and better suited for your azalea’s needs.

While most composts can be used safely with azaleas, ericaceous compost provides a much-needed environment for your azaleas to thrive. So, what exactly are the benefits of ericaceous compost? Keep reading to learn more about ericaceous compost and its potential benefits for your azaleas.

Why Do Azaleas Need Ericaceous Compost?

There is a group of plants that are lovingly known as “lime haters.” These lime haters cannot properly survive in lime-rich and alkaline soils, also known as high-pH soils. Azaleas are one of these plants.

Azaleas thrive in soils that range from neutral to very acidic, also known as low-pH soils. Ericaceous compost is a compost that is low in pH and perfect for lime haters. Without this acidity, azaleas will have a difficult time absorbing nutrients from the soil, leading to their leaves eventually turning yellow and dying.

The Benefits of Ericaceous Compost for Azaleas

As mentioned earlier, ericaceous compost is great for lime haters like azaleas, but what exactly are the specific benefits of ericaceous compost?

One benefit of ericaceous compost is that it holds onto moisture for longer than some other composts. While this may seem irrelevant at first glance, it is actually very important. Azaleas thrive in moist soil that doesn’t wet their roots to drown them but not so little water as to dry them out. Ericaceous compost holds onto just the right amount of water for azaleas, meaning you can easily skip a watering or two, and your azaleas will be more than fine.

Another benefit of ericaceous compost is how readily available it is. You can even make it at home by yourself without needing to go seek it out at a local gardening store. Being able to make your own compost at home is not only satisfying, but it allows you to cater to your individual plants’ needs along the way.

Another great benefit of ericaceous compost is that it is high in nutrients, minerals, and organic matter. While this might at first seem like a no-brainer, it is actually very useful in ways that amateur gardeners might not realize straight away. More nutrients for your beloved plant means fewer times you have to feed your plant.

There are many reasons why a plant may need to be fed: it could be in poor soil that lacks nutrients, it could be overwatered, and the nutrients have washed out, etc. While there are many reasons soil could lack nutrients, it is a great idea to give compost that is high in nutrients and can make up for any possible lacking.

The Downsides of Ericaceous Compost

While ericaceous compost is a great compost to choose from, there is one obvious downside. It is acidic, meaning if you wish to have alkaline plants, you should not use ericaceous compost in your garden. 

While there are many acidic-loving plants out there to choose from, such as azaleas, if you are thinking of adding alkaline plants or plants that need a high pH, you shouldn’t use ericaceous compost. 

Because ericaceous compost is highly acidic, it will very negatively affect your alkaline plants. No one like limitations on their garden planning, but mixing alkaline and acidic plants may be a bad idea, especially for a beginner gardener.

How Does Ericaceous Compost Compare to Other Composts for Azaleas?

Talking about ericaceous compost is great, but what if you’re a beginner who doesn’t know much about compost? How do you know how it compares to other composts out there?

Here we will compare ericaceous compost to three other common composts.

Compost TypeAcidic or AlkalineNutrient LevelSuitable for Azaleas?
Ericaceous CompostVery AcidicHigh in nutrientsYes, this compost is highly acidic and high in nutrients
Seed Compost (aka Potting Compost)Neutral to slightly acidicLow in nutrientsYes, but it is low in nutrients
Multipurpose CompostNeutral to slightly acidicOften high in nutrientsYes, but it can sometimes not be acidic enough
Bark Chip Compost (aka Wood Chipping Compost)Mildly AlkalineRelatively high in nutrientsNo, this is alkaline

The composts listed above, and most composts, can all be made at home, but some are far more difficult than others and may require a lot more patience and ingredients.

Myths About Ericaceous Compost

Like all great things in the world, there are rumors that circulate about ericaceous compost. While some rumors may be true, there are some rumors that are inherently false.

The myth: It is difficult to care for plants that use ericaceous compost.

The truth: False. Plants that use ericaceous compost are like any other plants: they need to be taken care of. You can’t plant something and then never touch it again. While many plants require care, such as watering, plant food, organic materials, and fertilizer, plants that use ericaceous compost are no more difficult than their counterparts.

The myth: Acidic composts are not good for the soil.

The truth: Absolutely not. In fact, some plants require acidic soil in order to thrive. Without acidity, the leaves of these plants would quickly turn yellow and begin to die before the rest of the plant began to feel the effects of soil that is too alkaline.

The myth: Ericaceous compost is more difficult to make than other compost types.

The truth: Not true. While compost can be difficult to make, depending on your experience level, the type of compost you are making, and the materials used, ericaceous compost is not more difficult than other composts. Composting of any kind takes a lot of patience and time to complete. It can take anywhere from two weeks to two years. Not to mention the amount of space it takes up, considering it is typically 2 meters, or 6 feet, high.

The myth: Ericaceous compost is good for any plant type.

The truth: False. As mentioned before, ericaceous compost is acidic, and not all plants need acidic soils. Some need alkaline soil, some need more neutral soil, and some do need acidic soil. It is important to understand the needs of a plant before adding it to your garden, less your brand new plant begins looking less new and more dead.

The myth: Ericaceous compost retains moisture, so you never need to water your plants. The rain will take care of that.

The truth: False. While ericaceous compost can help retain some moisture, you still need to keep an eye on your plants. Yes, if it has been rainy, you can probably skip the watering, but if their soil begins to look dry and sandy, it may be time to add some more water.

How to Create Your Own Ericaceous Compost at Home

Making compost at home is very satisfying, not to mention a great way to sometimes cut costs, as buying compost can become expensive easily, depending on how much you need for your garden.

Keep in mind that compost areas can be 2 meters or 6 feet high, so plan accordingly and choose your compost area location wisely.

  • Start with a pile of organic matter that is 10 to 20 cm, or 3.9 to 7.8 inches, high. Organic matter can be plant materials, animal manure, and/or food scraps.
  • All compost becomes alkaline if left alone. Since ericaceous compost is acidic, you will want to add plenty of pine needles, coffee grounds, and/or oak leaves to up its acidity.
    • Do not worry about adding too much acidity, as the longer your compost sits, the more it will try to become alkaline, so be generous with your acidity materials.
  • Next, you want to take a look at your compost area and measure its size. Then add 1 cup of dry garden fertilizer for every 1 square foot of compost area.
  • Next, add 3 to 5 cm, or 1.1 to 1.9 inches, of garden soil over the compost area. This will speed up the time it takes to decompose everything in your compost.
  • Finally, alternate between adding plenty of water and 3 to 5 cm, or 1.1 to 1.9 inches, of garden soil until your compost area reaches a height of 2 meters, or 6 feet, high.

Another important factor to keep in mind when creating compost is time. Depending on the materials used and the type of compost, compost can take anywhere from two weeks to two years to complete.

Remember to keep your compost area moist. If it is dry, it will not decompose. You will want to mix it to keep oxygen going every time you add more materials and water it when it seems to be drying out.

Some Alternatives to Ericaceous Compost for Azaleas

If you would rather not use compost at all, there are a few alternatives to keep your azaleas happy and healthy.

A great replacement may be peat moss or sphagnum moss. Both are acidic and a great alternative to ericaceous compost if you would rather not use compost. To use one of these mosses without compost, it is recommended you use 40% moss, 40% pine bark, and 20% light soil. 

You may also use sponge rock instead of light soil if your soil is hard or if it is clay. You will want to dig a hole that is three times wider than your pot and a few inches, or many centimeters, deeper than the pot. This is because azaleas have short roots and, therefore, do not need much space for their roots to grow.

Another great alternative to make your soil more acidic without ericaceous compost is organic soil sulfur. Organic soil sulfur is very soluble in humid environments, meaning it will begin working very quickly to make your soil less alkaline. 

Keep in mind that some people will use aluminum sulfate instead of organic soil sulfur, but aluminum sulfate is high in sodium. A lot of salt can lower the quality of your soil. It is recommended that you use organic soil sulfur instead of aluminum sulfate.

Another thing to remember is that this is typically a temporary quick fix. To lower the pH of your soil for longer, it is recommended you use other alternatives combined with organic soil sulfur.

Organic matter is another great alternative to compost. While this typically refers to compost, there are organic matters that are not compost, such as microbe food. Building up healthy microbes can make your soil more self-sustaining and less of a hassle you have to worry about.

If done right, soil can become almost completely self-sustaining. Keeping a healthy balance of organic matter and microbes, such as fungi, protozoa, bacteria, and nematodes, can become a permanent solution for your garden needs.

The last alternative to ericaceous compost is organic fertilizer. Fertilizer is a great go-to when your soil needs an extra pep in its step. However, it is important to keep in mind the salt content of your fertilizer. Try to avoid any fertilizer that contains salt, as lots of salt is bad for the soil’s health. As a general rule of thumb, all synthetic fertilizers contain salt and should be avoided.

Check out: Coffee Grounds for Azaleas


When it comes to azaleas, it is important to remember that they are acidic based and do not do well in lime-based, alkaline soils. Whether you’re starting your very first garden or are an experienced gardener, choosing the correct compost can feel a little tricky at first glance. In reality, however, it can be incredibly simple and very satisfying, especially when you opt to create your own compost.


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