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Ericaceous Compost: How to Make and When to Use

Can you make an ericaceous compost at home? It’s a common question.

Some plants thrive in all kinds of conditions and can be left to their own devices. However, some are like petulant children. They can be temperamental and throw tantrums when things don’t quite go their way. 

Take blueberries, for example. Blueberries are spoiled. They will only grow in acidic soil with a pH of 5.0. If you don’t get the pH level right, they’ll happily sit there all year, stunted, with their branches folded – which means no blueberry pie for you or me.

To make Ericaceous compost concentrate on producing a good batch of regular compost first. Once the compost starts to breakdown. You can ease off on the alkaline substances(tend to increase pH level) like Manure, Lime or Ash. And then add acidic substances like Oak leaves, Coffee Grounds or Sawdust.

An ericaceous soil in its simplest term is a soil that is lime free and acidic, and most people purchase it from the garden center, but its quite simple to make at home.

Let’s take a closer look at this acidic soil substance.

What is an Ericaceous Compost?

Soil is either acidic, neutral, or alkaline. The name Ericaceae comes from a family of flowering plants, more commonly known as the Heather family. This type of flower is known to grow in acidic soils, so an ericaceous soil by definition is acidic. 

Why do I Need an Ericaceous Compost?

Blueberries aren’t the only acid-loving plants. Rhododendron, Cranberry, Japanese Maple, Holly, and Ferne also fall into this category. 

They all love acidic soil. However, each plant has its own particular pH level, and if you’re not careful with your soil, these plants will struggle to take up the vital nutrients they need and may die. Wasting all your time and effort and can be extremely frustrating.

Most plants favor a slightly acid or slightly alkaline soil.

However, in specific scenarios, ericaceous soil may not be necessary. If you have tested your soil and you need to raise the acidity level, then don’t go digging it up to add a new layer of an ericaceous soil. You can increase the acidity directly by adding sulfur chips or powder to the topsoil. You can find sulfur in all garden centers and online.

Additionally, if you are potting plants, it isn’t necessary to make a whole batch of ericaceous soil. But if you want to, you should use 50% peat moss, 20% perlite, 10% regular compost, 10% garden soil, and 10% sand.

That is the perfect mix for potting plants to receive all the nutrients they need. Peat moss is an excellent amendment for potting soil because of its acidic pH and has been used for hundreds of years.

How to Make an Ericaceous Compost

It’s pretty much like making regular compost. However, be careful to keep it separate from any other compost you may have. Visually it looks the same as neutral or alkaline compost.

Concentrate on producing a good batch of regular compost first and then add other materials to make it acidic. It’s hard enough to get the green and brown material mix correct when producing a good pile of compost anyway, so trying to make ericaceous compost straight out of the gate is wishful thinking. 

It’s hard to judge the balance without the constant testing of pH levels. You will only end up with a nasty smelling pile of sludge at the bottom of the garden.

So remember, the basic rules for making good compost are:

  • The right balance of brown and green material. 3:1
  • Keep it moist
  • Mix it occasionally
  • Let it breath
  • Don’t make the pile too small

Once your compost has started to break down, then start to ease off on the following substances:

  • Manure
  • Lime
  • Ash

All these items tend to make the soil more alkaline — the exact opposite of what you are trying to achieve.

There are certain items you can add to the compost to make it acidic:

Fun Fact: It’s a common belief that pine needles are great for helping to make compost acidic. However, this just isn’t true. Although the pine needle itself is acidic when it’s on the tree, by the time it has decayed and broken down, its acidity level has actually returned to neutral. It, therefore, doesn’t contribute to raising compost acidity levels.

How to Measure Soil pH Levels

Some gardeners like to take this to the extreme. It’s entirely possible to send your soil to a lab to be tested by scientists if you want to, but why would you? 

It is incredibly expensive when you consider you can check the soil with products from around the home or purchase inexpensive testing equipment from the garden center. 

Of course, you will never be as accurate as a multi-million dollar laboratory, but it will give you a ballpark figure, but remember the proof will be in the plants, in the end.

To test the pH of your soil, you will need two items, distilled water, and a pH meter that you can purchase online at places like Amazon.com.

It’s important to note here that pH levels in soil differ in each area of the garden. 

Additionally, the ericaceous compost you have made will gradually return to a neutral pH level over time. That is entirely normal, and there is nothing you can do about it.

Use the following method for testing the pH level in your compost pile and your garden.

  • Choose an area to be tested and divide it into different sample areas.
  • Dig a six-inch hole, mix and break up the soil and return the soil to the hole.
  • Add the distilled water and insert the probes of your pH meter.
  • Leave for a minute and record your reading.
  • Repeat this above for the other sample sites and take the average as your pH level. 

If you would like a visual guide on how to test the pH of your soil, then view this helpful youtube video from the Alberta urban garden channel.

How to use an Ericaceous Compost

Once you have created your compost, it’s essential to use it correctly. Otherwise, your composting efforts will have been a complete waste of time.

Ericaceous compost decays over time and gradually returns to a neutral state. If you are using this for blueberries, for instance, you will need to top it up occasionally. 

You don’t necessarily have to produce more compost, but if you have it, then great. If not, you could use coffee grinds or citrus peel placed directly onto the soil. 

Just spread them on top and cover them with mulch. An additional benefit of mulch is that it will help keep the soil acidic for longer and stave of pesky critters who want to steal your citrus peel.

Pro-tip: try not to water the areas where you have ericaceous compost because tap water is alkaline and will dilute its acidity. Try to collect rainwater specifically for these areas as rain tends to be acid in nature.

If you know your garden and you know it tends to be alkaline, then adding ericaceous soil will be a frustrating task as it will always decay back to neutral. 

You will need to continually keep topping it up and keep adding citrus peels and coffee grinds. It might also be a better option to raise the bed off the ground or try using planters and plant pots. Keep your plants that need ericaceous soil segregated from the rest of the garden.

Do I Need Ericaceous Plant Food?

When ericaceous plant food is combined with acid compost, it can work wonders for lime hating plants. They provide your plants with the perfect balance of iron and essential nutrients to help them flourish and thrive. However, you can use regular plant feed if that is all you have available to you.

Final Thoughts

In the end, using this type of soil is a choice and not a necessity. You can design your garden is such a way that you never need to use ericaceous compost. 

But if you are brave enough, why not give it a go?

It’s inexpensive, and It isn’t too tricky either, and having acidic plants in your garden represents an exciting challenge that will help you to expand your gardening repertoire.