How big does a no dig bed need to be?

The beauty of no dig is that you can scale up or down very easily. A bed of 1.2m x 2.4m can grow a sizeable amount of food. If you’re starting out, that’s the size bed I’d recommend. I’m always saying, don’t take on too much. Start out small and you’ll make small mistakes.I like to think that people feel in charge of what they’re doing and not feeling daunted.

How do you create a no dig bed from scratch?

If you’re starting on lawn, put cardboard on top as that smothers the weeds, enough to stop them growing. Then put compost on top of that – say 10cm.

You can plant into that straightaway. The plants will root into the compost and eventually into the soil, once the cardboard has decomposed after around 10 weeks.

What type of compost can you use?

When I say compost, I mean anything that is decomposing. I’m not setting the bar too high here, as I think people believe it has to be perfect compost. But actually, especially if you’re making a new bed, you can put quite lumpy stuff at the bottom as long as you have 3-5cm of fine compost on top.

The origin of your compost can be anything from old manure to old leaf mould, the stuff you buy like green waste compost or mushroom compost, even really old woodchip if you can sieve out the big bits, or homemade compost.

Can you use bagged compost?

Yes, if that’s what you can get your hands on. And it’s fine to use an old bag of compost.

One thing you don’t read about is that there’s a shortage of compost at the moment as so many people are gardening. And it’s a bit too fresh and is still decomposing. One sign of this is that it feels warm in the bag. It’s not really ready to use as it’s still fermenting and is going to take nutrients for its own decomposition  before the plants can get them. I’ve had quite a few people reporting this year that they’ve made new beds and put in their plants and they don’t grow. Then about eight weeks later, they grow.

No dig involves less weeding – can you explain why?

If you disturb the soil, it needs to recover and it will recover itself with weeds. Farmers around here say that chickweed follows the rotavator. In no dig gardens you very rarely see chickweed. There are obviously some weeds, but far fewer. You have a chance to have a zero weed garden by just regular removal very quickly, before they set seed, and then you’re free to do other things.

What about slugs and snails?

Pests are a massive discouragement for people wanting to grow veg. No dig, by not damaging the soil flora and fauna, allows the system of pest predators to flourish. Diggers will say that we dig the soil to expose pests to birds. If you think about that, it makes zero sense as it implies you’re only exposing the pests. What about the earthworms, centipedes and spiders, and the mycchorizal network, which has been damaged?

With no dig, you get fewer slugs but you’ve still got to maintain the tidiness of your garden. It’s something I’m really big on. For example, removing the lower leaves of brassicas. It’s also better to not have sides on your raised beds. If they’re new, fine, but once the wood starts to decay on the inside where it meets the soil, it creates cavities in the wood that slugs live in – the perfect habitat on a sunny day, and then they come out at night and eat your plants. I’m always looking for the places where they hide by day to reduce their population – not to get rid of them, as we want the toad and blackbirds that might eat them.

Find the area in your garden that doesn’t have much habitat around it, if possible – if you plant veg next to your herbaceous border, they probably will be slugged. This can be a challenge in a small garden.

You often advise against sowing too early, and you sow most things in modules under cover first. Can you explain more about that?

I’m always advising people to not sow too early! I got an email this year from a seed company on 20 February, saying it was time to sow cucumbers. I actually recommend mid April, because the plants won’t get checked by cold conditions then and they’ll grow fast once you get them in the ground in May. In my book, I lay out the best sowing times for each vegetable. There is a lot of misinformation out there.

Can no dig work anywhere in the world?

I’ve had positive feedback from people in very different climates.  No dig is working brilliantly for a man in a tropical rainforest environment in the Philippines. He said he gets less erosion in the heavy rain and better moisture retention when it’s not raining. I’ve also had good feedback from the high desert of Utah, where they have very little rain. In really hot sun, I’d advise putting dry grass or hay on top, to protect the compost a bit. I’ve had lots of positive feedback from south India and Bangalore, and a lot from Canada and the USA. I had feedback from a lady running a rooftop garden on an office block in Singapore and she couldn’t believe how much fewer weeds she had.

Can no dig be applied to herbaceous border?

Totally. I think something like 80 per cent of British cut flower growers are no dig now. If you’ve got a problem with couch grass or ground elder in a border, cardboard is a useful way to tame it. You can butt cardboard right up to woody stems. You can cut cardboard like a jigsaw and put a little bit of compost on top to hold it down. That will give you a lovely weed free start. The later regrowth won’t be as strong and easier to remove. Weeds give up more easily when you don’t disturb them.

Do you think no dig is finally becoming more mainstream?

For years, it was all crop rotation and artificial fertilisers and chemicals, and looking back now, that just seems crazy and old fashioned. It’s all happened in the last few years. People find it easier to change the way they look at things if a lot of other people have done it. There has been a growing environmental awareness. I noticed a big shift in 2015, which was the year of the soil. People started looking at soil as an entity in itself. When I was going to lectures in the 1980s, lecturers would say that soil was like a bank balance – nutrients in, nutrients out, like it was a holding mechanism. Plus a lot of people have heard about the myccorhizal network now.