If you’ve ever wondered where plants get their nutrients, or how do plants eat you’ve come to the right place. We will look at how plants get nutrients, and what we can do to fascilitate this in our gardens by building healthy soil. Fertiliser-free gardening isn’t just possible; it’s how nature has been working for hundreds of millions of years. Plants have a deeply rooted, reciprocal relationship with the life in the soil that allows them to access nutrients. So how do plants eat, and how can we make this work in our gardens?
How do Plants Eat?
The soil is full of nutrients, but they’re tightly bound in the organic and inorganic compounds in the soil and aren’t directly available to plants. This is great news because it means nutrients don’t simply wash away when it rains, but it also means plants need help to get to them.
Enter the soil food web. Just like our gut microbiome helps us digest food and absorb nutrients, the fungi and bacteria in soil do the same for plants. These microscopic organisms break down dead organic matter like fallen leaves, twigs, and even animal waste releasing essential nutrients. They also interact directly with plant roots, helping them extract what they need from the soil in exchange for root exudates, a mix of sugars and carbohydrates plants produce specifically to attract helpful microbes.
How Fertiliser Can Disrupt the Balance
Now that we know how plants eat, we can make an educated guess as to what to do with our fertilisers. When we apply synthetic fertilisers, we short-circuit the natural nutrient cycle. Plants absorb the easy-to-access nutrients without needing to work with soil microbes. Over time, they stop producing root exudates, leaving the beneficial organisms with nothing to feed on. As a result, soil life declines, and plants become dependent on artificial feeding. This also means that the life in the soil doesn’t benefit from other useful services provided by the life in the soil like creating good soil structure.
This is why fertiliser-free gardening is so effective. Instead of constantly guessing when and what to feed plants, we can focus on nurturing a healthy soil ecosystem. When the soil food web is thriving, plants get a steady supply of nutrients without human intervention and without second-guessing whether we are getting the balance right.
The best thing is that plants can attract the organisms that they need to the area around their roots called the rhizosphere, in order to be able to access specific nutrients. So they never go without.
How do Plants Eat Without Fertilisers
If you’re starting a garden and wondering how plants eat or how often you should use fertiliser, consider skipping fertilisers altogether. Instead, build up the natural soil system by adding organic matter in the form of either compost or well-rotted manure. This will feed the soil life, encouraging plants to form their own relationships with microbes. Mulching, composting, and avoiding synthetic chemicals will keep the soil teeming with the right kinds of bacteria and fungi to unlock nutrients when plants need them.
Once you embrace fertiliser-free gardening, you’ll realise how simple it is. Instead of constantly monitoring your plants for nutrient deficiencies and adjusting fertiliser schedules, you can let nature do the work. Having healthy soil also helps build soil structure, makes your garden more drought-resilient and flood-resilient, and acts as a first line of defence against soil-born pests and pathogens. And the best part? You’ll have healthier plants and a garden that practically takes care of itself.
How Do Plants Eat without Fertiliser?
Imagine a beautiful, thriving woodland or rainforest. It produces a stunning amount of healthy plants and nobody goes into that forest and adds nutrients. Plants get their nutrients in the same way as we do in our gut microbiome, using beneficial microbes to break down our food. The only difference is that for plants their “gut microbiome” is on the outside, in the soil.
Should I Use Comfrey Tea or Worm Tea Fertiliser?
These fertilisers, whilst natural, will still interrupt the relationship between plants and the soil. However, you will still need to use fertilisers on pots and containers, so save these lovely organic feeds for this.
How Often Should I Mulch?
Mulching can be done once or twice a year, depending on whether your soil needs more or not. Soil that needs more organic matter will dry out quickly, or become waterlogged after heavy rain. It will feel compacted, or too light (depending on the type of soil). It will also struggle to grow healthy plants.
How Much Mulch Should I Use?
Around 7cm is a good guide for the first time you mulch. Too much, and nitrogen will leak out, and potentially become a significant pollutant. Too little and you might not experience the benefit. The more you apply (up to 7cm) the greater the benefit you will see, and if you want to add more than this, do it in stages spaced out over several months.
Can I do this without any mulch?
Yes, you can, if your soil is ok to start with. You might want to try bolstering your soil health with some green manure first. Try growing something like field beans to add nitrogen or alfalfa to break up compacted soil. This will help to improve the state of the soil, mitigating the need for mulch. It is better to just not dig than to dig in organic matter because digging breaks down the organic matter already ingested the soil, and harms the microbial communities.
Should I use Fertilisers in My Containers and Pots?
Yes. Plants don’t interact with the soil in the same way when they are in containers. Make sure to follow the manfacturers instructions and don’t apply too much or you could cause fertiliser burn.
Learn More about How Your Soil Works
If you want to know more, there is a whole section in my book Grow a New Garden all about how the soil works, how to treat the soil, how plants get nutrients and how we can make the soil work for us. The whole book is geared toward creating your outdoor space in a way that benefits you and the local environment. It’s full of simple-to-follow information that will help you become your own organic gardening expert.
I’d love to hear if you have any more questions about fertiliser-free gardening!
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