There are not many big ideas that come along in gardening. After all, horticulture has been much the same since for ever: sow seeds, add manure, water and feed, and kill pests. But now, something revolutionary could transform the staid old world of grow-your-own: vegan gardening.

Unless you’ve been living on Mars, you will be aware that veganism is on the rise: one in eight Britons now identify as vegan or vegetarian; record numbers have gone meat-free this month; and supermarkets and high streets – hello, Greggs – are helping to turn it mainstream. But did you know that gardening can be vegan, too?

Vegan gardening is essentially a super-organic method that avoids any animal input – from manure to fertiliser. It is an important part of the vegan movement; it means you’re doing your bit for the environment and producing clean, ethically produced crops that are safe to eat, while sticking two fingers up to animal farming. Once ultra niche, it is starting to enter the mainstream: the first vegan garden festival was held last September in Hampshire, hosted by Chelsea winner Cleve West, while Joseph Gibson’s Conscious Consumerism garden at Hampton Court flower show last July graphically illustrated the ruinous effects of animal agriculture.

Joseph Gibson’s Conscious Consumerism garden at Hampton Court flower show. Photograph: Alamy

In vegan gardening, you have to be mindful of what you put on your crops. Animal manures used to help plants grow can be contaminated with infectious diseases such as E coli and listeria, as well as persistent herbicides. While manure-borne salmonella or campylobacter could make you ill, persistent herbicides could kill your crops, which rather defeats the point of adding manure. Instead, make your own compost from layers of nitrogen-rich green material (grass cuttings, peelings, leafy prunings) and carbon-rich brown material (dry leaves, straw, card, shredded woody prunings), sourced from kitchen, household and garden waste. The pile needs to be moist and warm to decompose through microbial action. Turn with a garden fork every month or two, and in six months you should have enough black, crumbly compost to grow your plants in. (Using peat is vegan, but is generally believed to be environmentally unsustainable: peat bogs are carbon sinks and, once mined, take up to 100 years to regenerate.)

Jerusalem artichokes. Photograph: Alamy

It’s not just animal manure that should be avoided: many commercial composts and fertilisers contain animal products such as blood, fish and bone – byproducts taken from the slaughterhouse floor. To help sustain your plants, make comfrey-based liquid fertiliser: put chopped comfrey (or nettles, borage, seaweed or other nutrient-rich plants) in a bucket of water and leave it for a few weeks until it starts to stink. Dilute and decant over crops to add nitrogen, phosphorus and potassium, as well as vitamin B12. These are the three primary ingredients required for healthy plant growth – comfrey’s high potassium levels particularly aid fruit production.

It’s true that vegan gardening is harder work then conventional gardening, because it is unethical to nuke “pests” and diseases. But with an ecosystem of weed banks, cover crops and the consequent beneficial insects in place, you shouldn’t have to.

To make your soil as nutrient-rich as possible, sow green manure cover crops such as clover, mustard, phacelia and buckwheat. Ideally, your soil should always be covered (especially in winter) to stop erosion, and to harvest nitrogen from the air; rake back the green manure into the soil (the worms will drag the nutrients underground, while the cover crop roots will help break up the earth).

Crop rotation in a vegetable patch will help maintain soil health, avoid nutrient deficiency and stop pest and disease buildup: plant a green manure, then alternate annual crops of potatoes, legumes, brassicas and root veg followed by squash and sweet corn, on a four- to seven-year cycle. Chances are, if you’re tempted by vegan gardening, you’re a vegan yourself, so grow what might be useful additions to your diet: vegetables such as spinach or jerusalem artichokes are high in iron; broad beans provide protein and fibre.

There is one aspect of vegan gardening that is easier than conventional gardening: you don’t need to dig. Digging over wrecks the soil and its fauna, creating compaction and erosion. Hoe off weeds instead; you should get fewer weeds anyway, because digging creates a hotbed for weed seeds. But don’t take the “no-dig” rule too far: someone once asked me if it was OK to dig up your potatoes!

The really positive part of vegan gardening is the benefits for animals and insects; the aim is not to kill anything, and as far as possible leave garden wildlife alone. Insects and invertebrates (particularly worms) are essential parts of a garden’s ecosystem, whether they are maintaining soil structure or providing a link in the food chain.

Freshly-pulled carrots. Photograph: Getty Images

Instead, there are ways of dissuading the animals you don’t want from entering your garden. Don’t feed birds, as this will attract rodents. If you must, use barriers such as nets to protect crops from birds, or liquid repellants such as Grazers’ Live, and Let Grow deterrent sprays for anything from lily beetles to squirrels. Create habitats among cover crops and wild patches for those creatures you would like to see: beneficial pollinators, predator insects such as ladybirds, hoverflies, lacewings and ground beetles.

Slugs are a pain because they eat young, green plants, so plant these out when they are more mature and less attractive to pests. Plant sacrificial plants, such as lettuce or brassica leaves, as an alternative food supply to the crops you want to flourish; pick off slugs by hand (gently); encourage slug eaters such as hedgehogs with wood and leaf piles, and by planting hedges instead of walls or fences. And if slugs do eat your salad leaves and bugs munch your apples, leave them to it – now, there’s a new idea.

• Matthew Appleby’s The Super Organic Gardener: Everything You Need To Know About A Vegan Garden is published on 31 January, at £16.99. To order a copy for £14.95, visit guardianbookshop.com.

Insects such as ladybirds are highly beneficial. Photograph: Alamy