Walk into a garden center, and you’ll likely be greeted by a dizzying array of compost options. With so many choices, it’s easy to feel overwhelmed — and it can be hard to figure out which one is right for your needs.
This guide simplifies the process by breaking down 12 common types of compost, explaining their uses, benefits, and when to avoid them. You’ll also discover which types you can easily make at home. Whether you’re starting seeds, improving your soil, or tackling unique gardening challenges, this guide will help you choose the best compost without wasting time or money.
For a quick overview, check out the infographic just below. For in-depth guidance, keep reading!
Compost Types Infographic
For more detail (and more types of compost) read on.
Seed compost
In a nutshell: Seed compost is ideal for starting seedlings, offering low nutrients and good drainage. Multi-purpose compost also works for seeds but may reduce success rates for some varieties.
Seed compost is also known as potting compost.
Lower in nutrients than standard multi-purpose compost, it avoids excess nitrogen that can damage young roots.
It is also light and airy, carefully balancing the ability to drain water and provide oxygen while holding sufficient moisture for early growth. Typically seed compost combines standard compost with other ingredients such as coir or perlite.
Watch out for…!
While seed compost is generally low in nutrients, it does need some. Tests by Which! have found that pure coir composts which are not enriched with nutrients perform poorly. Seeds germinate in the composts, but fail to grow on afterwards. In contrast, the top performing compost in UK tests is Fertile Fibre Seed Compost.
Do you need seed compost for seeds?
Sellers of seed compost will say you need seed compost. While seed compost is undoubtedly the best option for seedlings, it’s not essential.
I’ve personally germinated many seeds in multi-purpose compost. Many seeds will also work if planted directly in the soil, albeit with a lower success rate. That said, a quality seed compost will give you the best chances of germination with more fussy plants
Can you make your own seed compost?
If you’ve made your own general compost, you can easily adapt it to create seed compost. Here’s how:
- Choose well-matured compost: Ensure it has fully decomposed and is dark and crumbly.
- Sieve the compost: Remove any woody bits or lumps to create a fine texture.
- Mix with other ingredients: Reduce the nutrient value by combining the compost with materials like coir (a mix of coconut fiber and perlite) or salt-free sand for a heavier blend. Aim for a 50:50 ratio of compost to other ingredients.
Some blogs suggest sterilizing seed compost, a method popular in the past that involved heating soil in an oven. While this can kill weed seeds, it may also remove beneficial microorganisms that support plant growth. Sterilizing is generally unnecessary unless you’re working with very sensitive plants.
Multi-purpose compost
In a nutshell: As the name suggests, this compost is suitable for most purposes, including starting many seeds and enriching soil. However, it’s not ideal for ericaceous plants, which require a more acidic compost.
Multi-purpose compost is designed for general garden use and is highly versatile. Common uses include:
- potting on seedlings and plants
- adding fertility to existing pots
- for hanging baskets
- enriching soil
- mulching
Store bought compost is finer than standard home made compost, and is sometimes enriched with plant food.
Many composts indicate how long their nutrients will last, but this should be taken as a rough guide. The duration will depend on factors like growing conditions and the types of plants you’re cultivating.
Can you make your own multi-purpose compost?
Yes, you can – and it’s easier than you might think. Making your own compost is a great way to save money, and it doesn’t take much more effort than bagging up garden waste for disposal.
That said, achieving the same quality as store-bought compost can be challenging. Commercial compost typically has an ideal pH level, excellent moisture retention and is often enriched with nutrients to support plant growth.
Personally, I use homemade compost for the vegetable garden, polytunnel, and established plants, while reserving store-bought compost for seeds, seedlings, and more sensitive plants.
Want to get started? Learn how to make compost with our Home Composting Guide
Manure compost
In a nutshell: Manure compost is any compost which is made from, or mostly from, animal droppings. It is a fantasic amendment for hungry plants such as squash, but is not suitable for all plants.
Manure compost is rich in nutrients and has been used for centuries to improve the soil. Applying compost manure to the garden can improve the structure of the soil, as well as it’s chemical and biological properties.
While there is limited research comparing manure compost with regular compost, my personal experience suggests that manure compost works wonders for nutrient-hungry vegetables like courgettes, potatoes, and leeks. However, it’s best avoided for vegetables such as carrots (which may fork in rich soil) and acid-loving plants like blueberries.
Do note that manure varies significantly in composition – see our guide to the different types of manure for more information.
Can you make your own manure compost?
Yes, and if you have access to manure it is very worth doing so. Compost manure in shops is expensive. In the countryside, though, farmers and equastarians often give it away for free, or will deliver a trailer load for a nominal fee.
As manure often contains straw, composting is it often simply a matter of piling it into a heap and leaving it for six months to a year. Turn once for optimal results. You can also add manure into your existing green manure bin or heap.
Peat Based Compost
In a nutshell: Peat compost retains moisture exceptionally well and provides excellent nutrients for plants. However, its extraction harms the environment and is banned in some countries.
Peat-based compost is rich in peat, a naturally occurring material formed from partially decomposed organic matter under waterlogged, oxygen-deprived conditions.
Peat has many advantages: it retains moisture, has the perfect texture for plant growth, and is nutrient-rich. Simply put, plants thrive in it.
However, the environmental cost of harvesting peat is significant. Peatlands store vast amounts of carbon – more than 600 gigatonnes, which exceeds the carbon stored in all the world’s forests—despite covering just 3% of the Earth’s surface. When peat is dug up, this carbon is released, contributing to climate change. Peatlands are also vital habitats for biodiversity.
Because of these environmental concerns, some countries have banned the sale of peat-based compost.
Peat based compost contains a large amount of peat. Peat is a naturally occurring material which is made up of partially decomposed organic material which has built up under water-logged, oxygen deprived conditions.
Peat-Free Compost
In a nutshell: Peat-free compost is simply an alternative to compost that contains peat, offering eco-friendly options for your garden.
As the name suggests, peat-free compost contains no peat. Your homemade compost is naturally peat-free, and there are plenty of peat-free options available in stores.
Store-bought peat-free compost typically combines organic materials with inorganic components like sharp sand and perlite, creating a mix that supports plant growth without harming peatlands.
I remember as a child, my father trying peat-free compost and complaining that it didn’t perform as well as peat-based options. Thankfully, composting technology has advanced significantly since then, and many modern peat-free brands now provide excellent alternatives that rival traditional peat-based compost.
Loam-based compost
In a nutshell: Loam-based compost improves soil structure, drainage, and fertility, making it ideal for a variety of gardening needs.
Loam is a type of soil that contains a balanced mix of clay, sand, and silt. Loam-based compost traditionally incorporates loam soil combined with peat and organic materials, though modern versions may use alternative ingredients to replace peat.
This type of compost is commonly used to enhance soil structure, improve drainage, and boost fertility. With its neutral pH level, loam-based compost is often a better choice than multi-purpose compost for plants that thrive in slightly alkaline conditions.
Can you make loam based compost?
Yes, you can! Making loam-based compost is straightforward and a great way to improve your soil’s structure and fertility. Here’s how:
- Combine Equal Parts: Mix equal parts of sand, silt, and soil to create the base.
- Add Organic Material: Incorporate materials like leaves, grass clippings, or composted kitchen waste to enrich the mixture.
- Moisture Balance: Add water as needed, ensuring the mix is damp but not soggy.
- Let It Decompose: Allow the mix to sit for several months until it’s fully decomposed. The finished compost should be dark, crumbly, and have an earthy smell.
‘Organic’ Compost
In a nutshell: The term “organic compost” is a misnomer—all compost is made from organic material.
You’ll also see compost marketed as organic. This is a misnomer, as all compost is made from organic material. Legally, the term organic can be applied to foods, but not to compost.
You’ll often see compost marketed as “organic,” but the truth is that all compost is made from organic matter. Similarly, labels like “chemical-free” can be misleading—everything, including compost, contains chemicals!
For more details and the best compost options for ethical and organic gardening, check out Organic compost: Black Gold or Commercial Hype?
Ericaceous Compost
In a nutshell: Ericaceous compost is specially formulated for acid-loving plants.
Ericaceous compost has a higher acidity level than regular compost, making it ideal for plants that thrive in acidic soil conditions. These include rhododendrons, azaleas, heathers, and blueberries, which struggle in alkaline soils.
Can you make Ericaceous Compost?
While it’s possible to make ericaceous compost at home, it can be challenging to achieve the right acidity without using some peat. Fortunately, the RHS notes that commercial peat-free ericaceous compost has improved significantly in recent years and is now a viable alternative to traditional peat-based versions.
Cacti and Succulent plant compost
In a nutshell: This compost replicates desert soil—well-draining and low in nutrients—making it ideal for cacti and succulents.
Cacti and succulent plant compost is specially formulated to meet the unique needs of these plants. It provides excellent drainage and low nutrient levels, replicating the arid conditions where they naturally thrive. (Note: While all cacti are succulents, not all succulents are cacti.)
Typically succulent compost contains soil, sand and/or grit as well as soil. It may also contain perlite and peat and/or specific plant nutrients suited for succulents. The mixes aim to achieve specific levels of PH balance, nutrition and drainage.
Typically, succulent compost contains a mix of soil, sand, and/or grit. Some blends may also include perlite, peat moss, or specific nutrients tailored to succulent plants. These components work together to create the ideal balance of pH, nutrition, and drainage.
Can you make cacti and succulent plant compost?
Yes, you can, although you’ll find some disagreement on the perfect mix! Simplify Gardening has an excellent article on the different materials you can use, as well as the mixes you can use for different types of succulents.
Bark Chip/Wood Chippings Compost
In a nutshell: Made from bark or wood, this carbon-rich compost is ideal for mulching and long-term soil improvement but unsuitable for ericaceous plants.
As the name suggests, bark chip or wood chippings compost is made from bark or wood, often combined with other organic materials. It is high in carbon and lower in nitrogen compared to standard multi-purpose compost, giving it a more alkaline nature, which makes it unsuitable for acid-loving plants like rhododendrons and blueberries.
This type of compost is commonly used for mulching, where it:
- Supports long-term soil improvement
- Improves soil structure and drainage
- Slowly releases nutrients into the soil
Wood compost can also promote beneficial fungi in the garden, more so than composts made from green manure. I’ve also found that adding wood shavings to my compost heap as a brown material has encouraged fantastic mushrooms to grow in my polytunnel—including some delicious edible varieties!
Bonus Tip: You can also create leaf mold compost, another high-carbon option that’s easy to make (though it requires patience). Learn how to make it here!
Can you make your own bark chip compost?
Yes, you can! Composting wood chippings is not only feasible but also economical if you have access to free or low-cost wood waste from wood yards or tree surgeons. With a large enough pile, you can even generate significant heat—wood chip piles have famously been used to heat houses!
Key Considerations:
- Quantity Needed: If you require a substantial amount of compost, building a large pile (at least 1 meter high and 2 meters wide) is more cost-effective. However, if you only need a small amount, purchasing bags of ready-made bark compost might be more practical.
- Alternative Uses: Wood chips can also be used as paths between vegetable beds. Keep the layer thin to minimize nitrogen depletion in the soil. Over time, the wood will suppress weeds, decompose, and gradually enrich the soil by releasing carbon and nutrients.
Biochar compost
In a nutshell: Biochar compost combines biochar with organic materials to boost soil health, improve yields, and reduce toxic metals in the soil.
Biochar compost refers to either compost made with biochar as an ingredient or biochar used during the composting process.
Biochar itself is a substance created by burning organic material from forests and farms. The burning process, called pyrolysis, uses very little oxygen, which helps minimise carbon loss. The result is a material which looks like charcoal, but is a more stable and cleaner form of carbon. It also has a high cation exchange capacity, which means it is much better at holding onto nutrients than typical garden soil.
Although more research is needed into biochar, some studies have shown that the use of biochar compost can have major benefits for soil. For example, one study by Antonangeloa, Sun and Zhanga added biochar to the composting process. They found that after adding the finished compost to garden soil, soil health improved and crop yields improved by up to 300%. The same study found that biochar helped reduce the amount of toxic metals in soil.
Another trial was conducted in two vegetable gardens in Wales. In the trial, biochar was added to a low nutrient compost. Although less dramatic, the results were still positive, with an average 14.8% increase in yields.
It’s worth noting that biochar is nothing new – indigenous Amazonian farmers have combined biochar with organic material for centuries.
Benefits of Biochar Compost
While more research is needed, studies have demonstrated significant benefits:
- A study by Antonangeloa, Sun, and Zhanga showed that biochar-enriched compost improved soil health and increased crop yields by up to 300%. It also reduced toxic metals in the soil.
- A Welsh trial added biochar to low-nutrient compost, resulting in a more modest but still impressive 14.8% increase in yields.
It’s worth noting that biochar isn’t new – indigenous Amazonian farmers have been combining biochar with organic materials for centuries to enrich their soils sustainably.
Can you make your own biochar/biochar compost?
Yes, biochar can be made both in metal drums and in trenches. It is a fairly involved process and unlikely to be as efficient as that made commercially. If you have the time and energy, it should be fun, but otherwise it’s probably easier to purchase.
However, you can also add biochar to your compost. As we saw in 16 Ways to Speed Up Compost, research suggests that adding as little as 3% can improve the speed of your composting process.
Learn more: How Biochar Can Help Improve Compost Speed and Quality
Sheep Wool Compost
In a nutshell: Sheep wool compost offers excellent water retention and slow-release nitrogen, making it a sustainable alternative to peat-based compost.
Sheep wool compost is made from sheep’s wool, often combined with materials like bracken. This unique blend provides several benefits:
- Water Retention: The wool absorbs and holds moisture exceptionally well, reducing the need for frequent watering.
- Slow-Release Nitrogen: As the wool breaks down, it gradually releases nitrogen, nourishing plants over time.
In recent years, the plummeting cost of sheep wool has made it a more viable material for compost production. This sustainable alternative not only supports eco-friendly gardening but also helps repurpose a resource that might otherwise go to waste.
Can you make sheep’s wool compost?
Yes, you can! Sheep’s wool can be combined with other composting materials to create a nutrient-rich compost.
One experimental study found that the best results come from a mix of:
- 25% sheep’s wool
- 50% grass clippings
- 25% manure
It’s important to separate any compacted wool before adding it to your compost, as this helps ensure even decomposition.
You can also compost sheep’s wool used in packaging. From my own experience, pulling the wool apart beforehand is essential—if left compacted, clumps of uncomposted wool can appear when you turn the compost. However, unless you have access to specialist equipment, composting large amounts of wool can be quite labor-intensive.
Mushroom compost
In a nutshell: Mushroom compost is a nutrient-rich, alkaline compost made from straw, chicken manure, and sometimes peat. It’s excellent for soil improvement but should be used sparingly in alkaline soils.
Mushroom compost is a byproduct of mushroom farming and is highly valued by gardeners. It is typically made from straw and may include chicken manure, with peat occasionally added. To increase alkalinity, chalk is often used.
This results in a compost with a high organic content and a medium nutrient level, as the nutrients are partially depleted during mushroom cultivation. Most mushroom compost is sterilized before being sold to ensure quality.
Nutritional and Chemical Profile
A study by Fidenzal et al. in Pennsylvania analyzed fresh mushroom compost and found:
- pH: 6.6 (ideal for many plants)
- C:N Ratio: 13:1 (optimal for garden compost)
However, the exact composition can vary based on the materials used.
Usage Tips
The RHS advises caution with frequent use of mushroom compost, as it can cause chalk buildup. This is particularly problematic for gardens with alkaline soils. Occasional use, however, is unlikely to cause harm and can help improve soil structure and fertility.
Charles Dowding Compost Comparison
No Dig guru Charles Dowding has run several planting trials on different types of compost, and ironically just as I was finishing off this post he came up with another one.
This trial compares the differences between soil, mushroom compost, wood compost (sieved and unsieved), green waste compost and Moorland gold. It’s a particularly interesting take as it looks at using compost for a longer period of time (with a second crop of leeks following potatoes).
Which compost brands are best?
If you decide to buy your own compost, you’ll want to know the best brand. However, it is hard to recommend brands, because results can vary from year to year.
In planting tests compost brands seem to perform differently from year to year, while lab analysis commissioned by companies such as Which! show that even respected brands may occasionally have some pesticides in them.
(I do recommend checking out the compost buying guides on Which!, although unfortunately there is a paywall.)
That said, it is worth avoiding some of the very cheapest brands, which can come filled with bits of plastic. If they don’t sift plastic from compost, it’s unlikely they take other measures to eliminate pesticides and ensure quality!
Here in the UK I have always had excellent results using John Innes compost, and I find this has a good balance between quality and price.
Dalefoot compost, which rather uniquely is made from sheep’s wool and bracken and is also recommended by Which!, would be my first option for smaller amounts of compost.. (Which!’s top choice, at least for seed compost, is Fertile Fibre. Although I haven’t tried this one yet, it has performed amazingly well in lab and growing tests.)
Wrapping up
There are many different compost types. Given the length of this post, I’ve covered some of the most common types here, rather than every one. Let me know if this works for you – if you think it should be expanded with types such as worm compost, leaf mould compost, manure compost and more, just get in contact 😉
The Types of Compost mini infographics by CompostMagazine.com is licensed under a Creative Commons Attribution 4.0 International License. It can be re-used with attribution to this post.