It is often a challenging task to choose the right compost for your garden, especially when you are a beginner. With such a massive list of options available, knowing which kind is best suited for your flowers or plants can be overwhelming.
In most cases, the key is to consider the preferences of your plants in soil. Even the smallest difference in pH levels and nutrients can affect the suitability and growth of your garden.
In this guide, I’ll show you some basic facts about ericaceous compost, one of the most common options for acidic plants, and how to make it yourself.
What is ericaceous compost?
Ericaceous compost is the most common type that most gardeners often come across. The name is derived from the Ericaceae family, which includes those plants that mainly grow in acidic and infertile soil.
Thus, ericaceous compost is simply a substance which is used to create a favourable living conditions for acid-loving plants, such as rhododendron, camellia, blueberry, cranberry, gardenia, azalea, hydrangea, Pieris, magnolia, viburnum, holly, lupine, bleeding heart, fern, aster, juniper, pachysandra, and Japanese maple.
Why do we need ericaceous compost?
Soil can have different pH levels, ranging from alkaline, neutral to acidic, with each one being suitable for particular plants. If you plant any acid-loving flowers or trees mentioned above in limey or alkaline soil, they will produce yellow leaves due to lime-induced chlorosis. As a result, these plants can’t grow well and eventually die.
The easiest way to acidify your soil is to use ericaceous compost. With a high amount of iron and other nutrients which are insoluble in high-pH soils, this type of compost can help reduce the pH levels over time and create an ideal environment for your plants.
Common ingredients to make ericaceous compost
Here are a few common ingredients that you can mix to make your own ericaceous compost:
a. Oak and beech leaves
These are a good source of essential carbon to make compost. Both beeches and oaks belong to the Fagaceae family whose foliage would acidify the soils when it gets decomposed. These leaves often require approximately two years to turn into mould. To accelerate the process, you can chop them up into small pieces, keep the mixtures moist, or add nitrogen sources such as manure, food scraps, and grass clippings.
b. Pine needles
Pine needles are increasingly becoming a popular option for garden mulch. While red, fresh needles are often used as mulch for the garden bed, newer ones can take more time to decompose. Gray and dingy pine straw bales are not attractive as mulch, but they are ideal for composting.
c. Coffee grounds
Many studies have proved that coffee grounds contain a high level of nitrogen, which can reduce the pH level in soils. By adding them into your ericaceous compost, you can allow pine straw and autumn leaves to break down quickly.
d. Peat moss
When combined with ericaceous plants in the soil, peat moss can improve the acidity in soils and promote healthy development. However, keep in mind that peat is typically a finite resource which takes centuries to grow. This means that it can be costly to make your ericaceous compost with this ingredient.
How to make ericaceous compost
There is no one-size-fits-all recipe for making ericaceous compost, and it mainly depends on the specific requirements of your plants as well as the current pH levels in the soil. However, the standard formula is quite similar to regular compost with some basic ingredients mentioned above.
Firstly, you’ll need a good compost bin. You should begin the compost pile with a layer of organic components in six to eight inches.
To improve the acid content, it is advisable to mix high-acid ingredients such as coffee grounds, pine needles, or oak leaves. Even though compost will eventually revert to a neutral level of pH, the inclusion of pine needles can help acidify the soils until they get decomposed.
Next, measure the entire area of your compost pile and sprinkle dry fertiliser on the pile. The ideal rate is approximately 1 cup for each square foot. Remember to use a fertiliser which is specially created for acid-loving plants.
Spread a layer of soil in your garden over the pile so that the microorganisms can speed up the decomposition process. In case you do not have enough garden soil available, consider using finished compost. Keep alternating layers and watering after every layer till the compost pile reaches 5 feet in height.
Useful tips to use ericaceous compost
Keep in mind that the effects when you combine ericaceous compost with soils in your garden are just temporary, meaning that the compost will lose its acidity over time. Thus, it is necessary to check the pH level frequently to make sure you still deliver the right condition (from 4 to 5 pH).
Maintaining the acidity isn’t hard as you can add acidifying materials such as mulch, leaf mould, bark chippings, and pine needles.
Tap water contains alkaline, so do not combine it with your ericaceous soil or use it to water your acidic plants. Instead, collect rainwater for irrigation purposes to maintain the level of acidity in the soil. If necessary, consider adding vinegar to tap water to mimic rainwater. However, it can be costly and time-consuming.
If the level of pH is too high or your garden is quite large, it’s better to use ericaceous compost in containers or pots. This will reduce the amount of compost you need to use. More importantly, it gives you the freedom to position your plants in suitable areas with shade, an ideal condition for acidic-loving plants to grow.