Composting tips, advice and science.

Making compost on a farm.

Why Homemade Compost is (Usually) Better Than Store-Bought Compost

If you’re considering composting, you may be wondering whether the money savings are worth the effort. 

First, it’s worth noting that if you have a large garden and mulch the beds to improve soil structure, those money savings can really add up. But that’s really not the only benefit to homemade compost. 

So in this post, we’ll dig into why homemade compost often comes out on top – and when store-bought might have its place.

For me, the top reason homemade compost stands out is its microbial activity.


Compost created at home is usually produced at lower temperatures compared to industrially produced compost.

This means it retains a vibrant, diverse community of beneficial microorganisms that promote soil structure health and make nutrients available to plants. What’s more, those microbes are native to your garden, meaning they are already well adapted to your soil and climate. 

Store-bought compost, on the other hand, is often produced at very high temperatures, which can kill off many of those microorganisms.

While this process makes it safer and more consistent, it also reduces the microbial diversity. With homemade compost, you’re adding living biology to your soil, which in turn benefits soil structure and plants.

You control what goes into your compost

Kitchen Waste in a compost bin.

Research has shown that vegetables grown in compost are healthier than vegetables grown in soil treated with only fertilizers. However, you can go one step further by ensuring that only quality ingredients go into your pile. 

In contrast, compost companies often accept many different materials to make bulk compost. In the past, this has led to contamination with microplastics and heavy metals, which can affect the quality of the compost. 

Herbicides are another concern. Most break down in compost, but one type of herbicide, called aminopyralids, stays in compost.

As I know from bitter experience, these can completely ruin a growing season, and there’s little research into the human health impact of them either. Aminopyralids are a particular growing concern at present, with increasing reports of them being found in bagged compost.

That’s not to knock the (good) compost manufacturers. I know they take every effort to minimize contamination, and many now test for aminopyralids. But despite their testing procedures, they lack something you don’t—a source of organic material from your own garden and kitchen. 

Avoiding plastic contamination

Homemade compost also allows you to steer clear of plastic contamination. Some store-bought composts have been found to contain small fragments of plastic, often from improperly processed waste streams.

These tiny pieces of plastic can accumulate in your soil and potentially harm soil organisms and plants over time. In contrast, studies have shown that home made compost have a very low level of unsuitable materials.

By controlling the materials that go into your compost, you can ensure it remains free of any unwanted contaminants and minimize the risk of micro-plastics entering your soil.

Your health

Father and daughter retrieving finished compost.

Making compost gets you outside in the fresh air and moving in the garden. If you turn compost (and you can make it without turning it), you’ll get a major workout. But there’s also some fascinating emerging evidence that the bacteria in compost can help us. 

For example, one bacterium that has been found in compost, Mycobacterium vaccae, has been found to lower brain inflammation, prevent post-traumatic stress disorder, and act in a similar manner to antidepressants.

While we need more research into the link between compost and soil bacteria, I think there’s little doubt that composting, just like gardening, can help with our health. 

When store-bought compost shines

Line of compost bags.

While I will sing the praises of homemade compost all day long, there are a few scenarios where store-bought compost can be a better option.

First, it can sometimes be a challenge to produce the quantities you need for your garden.


Secondly, transforming homemade compost into seed compost is a little more challenging than just making compost. It requires maturing the compost for longer, sieving it to get a finer mixture, and then mixing it with other materials for the final result.

If, like me, you’re often short of time, seed or potting compost can be a lifesaver—and a bag or two of compost is far more affordable than the couple of tonnes you might need to mulch your veg patch.

While I’m the frugal sort, this isn’t an area where I skimp. Cheap compost can often contain visible plastic—I’m happy to invest some of the savings I make from making my own mulching compost into high-quality potting compost.

Finding balance in your garden

Vibrant vegetables collected from a garden.

The best approach might be a mix of both worlds. Use your homemade compost to enrich your garden beds, support microbial life, and build long-term soil health. For tasks that require fine-textured compost, like seed starting, supplement with a bag of high-quality store-bought compost.

In the end, composting is all about closing the loop—turning waste into life. Whether you’re tending a backyard bin or scooping from a store-bought bag, you’re taking a step toward more sustainable gardening.

But if you’ve got the time, space, and materials, nothing beats the earthy goodness of homemade compost. It’s alive, it’s local, and it’s yours.

Happy composting!

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