Start no dig, soil types, weeds, composts to use

Fewer weeds in no dig

Whenever soil is dug, loosened or turned over, it recovers from the disruption by re-covering with weed growth – both from roots of perennials and seeds of annuals.  By contrast when left uncultivated it has less need to re-cover and therefore grows less weeds, as shown by a look at Homeacres at any time of year.

There are always a few new weeds,  from seeds blowing in or brought in with composts, and they need removing by hand when small, or hoeing off as tiny seedlings. It is a little and often approach. Vegetable growing is bountiful and easier when weeding is just a small issue, small but still important.

Mulching to clear soil of weeds in polytunnels is the same story, see my early posts of 2013 for how I mulched a tunnel of weeds, starting here and scroll down halfway. See Ferryman Polytunnels for some ideas of structures and prices, and my article on this site.

See this page in Italian, here.

Soil condition, firm is good!

Soil compaction is thankfully rare. Often soil feels firm or even hard, especially when dry, and this is fine for plants to grow in. Within the firmness is a tight structure of fine air channels and root passageways, as well as good drainage capacity. Even in clay, and I write this from experience, you need to trust!

Plants root better in dense, firm soil than in one whose structure is loose and offers less support to the plants above, and loses more moisture to evaporation. No dig works well on clay soil, see below.

Clearing weeds

The first step depends on how many and which weeds you have, especially perennials, and how much organic matter you can source – see this link for a depth calculator of compost.  The mulch(es) you lay are to clean soil of weeds by a smothering, light-deprivation effect. Mulches of organic matter also feed soil and its inhabitants.

There is no need to dig before starting, or to incorporate manure at depth. Placing organic matter on top is the best way to bring soil alive because that is how soil organisms work, searching for and eating organic matter at the surface, then digesting and excreting in the soil, building a permanent structure in so doing. Incidentally, worms love working under black polythene, if you are using that initially.

In damp climates such as the UK, I recommend not using mulches of undecomposed organic matter, such as straw, which allow slugs to hide by day and eat your plants by night. Where slugs are potentially prevalent, compost is the mulch of choice because it does not harbour slugs. Composted beds look ‘bare’ when not growing vegetables, but the compost mulch is protecting soil below.

The time needed between mulching and sowing can be instant if you have enough compost, say a 6in (15cm) layer (option 2 below), otherwise within 6-12 months as in option 1, depending on the current perennial-weed situation, and whether the timing works for vegetables such as squash and potatoes.

Some weeds that need digging out initially

Docks and woody plants such as brambles are best removed with a sharp spade, before mulching. Otherwise they push mulches up and reach light before they die. Use a sharp spade to cut around bramble clumps, removing the main crown but leaving all small roots in the soil. For docks, remove the top 6in (15cm) and then they do not regrow; I put these roots on my compost heap and they break down nicely.

Wooden sides?

Its often assumed that growing in beds means you need permanent sides, but this is untrue, though they are sometimes useful, for example in the first 6-12 months of option 2. Temporary sides (such as old fence posts) help to keep compost-filled beds in shape, for the first few months, as in the first photo of option 2 below, February 2013, I then lifted off the unfixed wooden sides in early autumn of that year, once the beds’ compost had settled and path weeds were dead – this had needed a further laying of cardboard in May, and again in July for a few places with couch grass.

It’s quicker and cheaper to create open-sided beds, and they offer less hiding places for slugs and woodlice. However, you must have weed-free paths for this to work and absolutely no grass, which otherwise invades beds with no sides. This is why I used cardboard on paths in the first few months at Homeacres, to kill buttercups, dandelion and some couch grass. After six months or so, once those weeds had died from lack of light and the cardboard had mostly decomposed in situ, I spread some organic matter as surface mulch: half-rotted leaves, old straw, green waste compost and decomposing woody material are suitable. Then I treat paths like the beds, they receive a little compost from birds kicking it off the beds (looking for worms), and I weed where necessary, to keep them immaculate.

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OPTION 1 Some organic matter and polythene mulches

See the video for more on this

When significant perennial weed roots are present and you are using say 1-2in (3-5cm) compost, there are still possibilities for growing veg in the first summer. Occasionally, slugs may make this tricky.

1) Initial soil feeding and  mulching of weedy  plots

No Dig Growing Basics
Experimenting with different surface mulches on soil with couch grass, buttercups and cow parsley.

Any organic matter can be applied on top, for soil food and to increase the light deprivation of weeds below. Animal manures partly decomposed, composts of any kind, a small amount say no more than 25% of leaves and grass clippings, are all good at this stage for feeding worms which get busy under dark mulches. Soil is improving at the same time as weeds are dying off. The surface mulch of polythene, cardboard or paper is applied on top of the organic matter.

Polythene can be 600 guage or thicker plastic of any colour (cheapest option), woven polypropylene membrane (best not cut) or landscape fabric which is cheap, light and easy to cut. However fabric lets 30% light through so best lay cardboard first, then fabric on top.

This option is particularly worthwhile if you are clearing vigorous, perennial weeds in summer or autumn, to have ground clean for the following spring. Or if you want to grow say potatoes and/or winter squash – see the photos below from Homeacres in 2016, taking a harvest of Crown Prince winter squash from ground that in April was 100% weeds including some couch grass (Elymus repens), grass and some bindweed too.

2) Next step depends on compost depth and weeds

Before removing polythene or membrane, allow enough time for weed roots to be exhausted under whatever mulch has been used. Annuals need two to three months, many perennials take from six months or sometimes longer, for their roots to be exhausted by trying to grow in darkness. If you peel back a mulch and still find white stems of weeds, their roots are still alive, as in the last photo of the four above. At least in this case, there was not a lot of bindweed and we used a trowel to remove those shoots, to further weaken the parent roots below.

At Homeacres, on pasture full of perennial weeds, I remove polythene mulches after one growing season, say February to October at most.

Carpet applied to weedy pasture three months earlier, with 1in (3cm) old horse manure. Bindweed Convolvulus arvensis is still growing white stems and leaves. White because they cannot photosynthesise, therefore the parent root is weakening all the time.
Carpet applied to weedy pasture three months earlier, with 1in (3cm) old horse manure. Bindweed Convolvulus arvensis is still growing white stems and leaves. White because they cannot photosynthesise, therefore the parent root is weakening all the time.

3) Normal Growing

After polythene/cardboard/membranes have done their job, you have a clean surface to sow and grow, which is the dark surface layer of compost you applied earlier, or apply afterwards. Seeds germinate and plants grow initially in the surface compost, then root into undisturbed soil below, which is firm but not compacted.  Firm is good!

Incidentally,  in dry weather soil becomes hard: this is normal and don’t worry, it softens with rain or watering.

Some perennial weed roots may still be sending up new leaves, as happened with the bindweed after my carpet mulch. In this case you need to keep removing the regrowth, as often as possible, to weaken the parent root even more. By year three, even bindweed is rare and easily manageable.

OPTION 2 using 4-6in (10-15cm) compost to create beds

When you have enough compost to create beds with up to six inches (15cm) on top of  weeds, this is sufficient to prevent re-growth of weeds.
An exception is if there are extreme amounts of bindweed, marestail and dense couch grass – in which case, use option 1 above.

6in/15cm compost well trodden, or less with thick cardboard underneath, is  enough to kill annual grasses and weeds, and to weaken if not kill perennial weeds such as buttercup, dandelion, and smaller amounts of couch grass. Use a trowel to remove any regrowth of perennial weeds, until parent roots die from lack of photosynthesis-food from new leaves.

  • Cardboard for paths only, temporary wooden sides: In the photos of Homeacres 2013, I used a wheelbarrow to fill beds with 6in/15cm depth of compost. This was two year old cow and horse manure, homemade compost, and some green waste compost for the top inch or two. Any fine compost is good for the surface layer, your own if it has reached that stage, or old cow manure, mushroom compost or store-bought compost.
  • For the large area to mulch in 2013, I had only enough cardboard for the paths and to go under the temporary sides. If I had been able to source it, cardboard laid over the bed weeds as well, before compost, would have slowed regrowth of buttercups, thistles etc. A few pushed through the compost and I needed to pull them in spring, until the parent roots expired.
  • The wooden “sides” you see above are fence posts laid on the ground, to hold compost in place while it settles. Before the end of that first year, I had removed most of them, as they are not needed any more and were giving habitat to slugs.

  • In the image of a new bed below, half the bed had cardboard under the compost, half did not and in this case it made little difference to weed regrowth, because the perennial weeds were not too vigorous, having been regularly mown for three years previously. If there are vigorous perennial weeds, a cardboard layer is worthwhile – thick cardboard is best, or two layers of thin cardboard. We filled this bed with half animal manure (old) and half my own compost, no green waste.
Filling a new bed on grass, one half with cardboard: the six inches of organic matter in this bed was enough to kill grass, dandelions and buttercups
Filling a new bed on grass, one half with cardboard: the six inches of organic matter in this bed was enough to kill grass, dandelions and buttercups

For an approach like this and to grow potatoes at the same time, see Naomi Schillinger’s blog of summer 2012.

Vegetables are hungry plants and require a soil that is well structured and full of life. First year dressings of organic matter may seem a lot but will repay the effort for years to come. Until the advent of chemical fertilisers, larger amounts of compost and manure were always used for vegetable growing. Since 1945 especially, more emphasis has been placed on chemical nutrients from synthetic or concentrated sources, but these fertilisers cannot provide soils with food for all its myriad of inhabitants who are so necessary in growing healthy plants. And some of their nutrients leach away in rainfall, which is both a waste and a pollution.

These parsnips were sown in well decomposed manure on top of heavy clay soil
These parsnips were sown in well decomposed manure on top of heavy clay soil

No dig clay soil no problem

At Lower Farm my soil was clay, and I found that all vegetables rooted into it. In France I gardened on dense white clay, with lovely harvests.

Clay soil is great for no dig: worms and other soil life improve its structure, you save so much time, and there is good nutrient + moisture retention.

To clarify, my clay soil at Lower Farm was in 2010 growing vegetables as in the middle picture and parsnips as in the right hand photo of the gallery below. No dig, no loosening or forking, just soil organisms doing the work and they are fed with a compost mulch. Parsnip and other seeds are sown into this compost.

At Homeacres my soil is dense silt and everything roots into that too. In my first garden 35 years ago, soil was Cotswold brash, very stony, and no dig was successful there as well.

Undisturbed soil develops and maintains a honeycomb structure of small air passages, especially when it is fed annually with an inch or so of compost on top. This compost can be animal manure that has been stacked for six months or more, your own compost, municipal or mushroom compost, leaf mould etc

  • Wood chips A variation  is to apply 6-12in (15-30cm) of wood chips, and/or bark and/or shavings, to kill off weeds. If you have access to these materials for free, its worth considering.
    But the downside is a wait of up to two years before the lower layers have turned to compost, by which time you can plant (easier than sow) into that lower layer, with the surface wood continuing as weed-suppressing mulch and eventual soil food. Lots of wood mulch encourages woodlice and they nibble leaves such as spinach and cucumber.

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No dig ongoing

The surface layer

Sowing small seeds into large lumps of compost and manure is unlikely to succeed, so keep the most crumbly and finest  organic matter for your surface layer of mulch.

Likewise, an excellent time to spread compost is in autumn, as soon as the previous crops finish. Then there is time for frost to break up any lumps and for worms to start taking it down, leaving a fair tilth by spring. It also helps, when the surface organic matter is lumpy, if you knock it around in February or March with a fork, just on the surface, to smooth out the lumpy bits.

Whenever you are spreading an inch or two of compost as surface mulch, break up any larger lumps, aim for golf-ball size as the largest, then weather can do the rest. I find that carrot and parsnip seeds germinate readily when sown into reasonably fine compost, then make straight roots down into the undisturbed soil below.

Maintaining abundant growth and few weeds

For vegetables, including for two crops in one year, average amounts of compost used annually are one to two inches on beds. Using less compost is possible but creates more work proportionate to results, through weeds growing, less healthy growth and smaller harvests.

For paths, you can spread an inch or two of wood shavings or sawdust, or leaves, straw, bark or less rotted manure. When growing without sides, the crops in beds root happily into weed-free, mulched paths in search of food and moisture. A caveat to this is areas with slugs, where path mulches should be more decomposed, to afford less habitat for molluscs.

Spreading compost in May after clearing winter cauliflower
Spreading compost in May after clearing winter cauliflower

Organic matter can be spread at any time of year.
The most practical season is autumn, when soil is moist and still warm, so that worms can access it, and when harvests are finishing and soil is cleared of crop remains. Also, some ground becomes clear in spring after winter leeks, cabbages and so forth, and can be composted then if there is no remaining organic matter on the surface. Or you can spread compost in winter between leeks and broccoli.

I find that one composting a year is sufficient for two crops, once soil is in good heart. You can tell this by how healthy and vibrant your vegetables are looking.

Where to find the organic matter you need? Compost is becoming more available, and often cheaper, thanks to recycling of green waste, and there are surplus quantities of animal manure to be found in many localities, in addition to any compost you can make.

Animal manures/composts

All are suitable, at least a year old, preferably dark in colour, with lumps that can be broken up by knocking with a fork before spreading. Old animal ‘manure’ is ‘compost’ and these two words cause confusion unless one is precise. Fresh manure is not compost, but old manure is. All organic materials such as leaves can turn into compost, when stacked for sufficient time in a heap with some air. Tree leaves take up to two years to compost, or one year when added to green/nitrogenous materials such as grass. They also decompose more quickly if chopped by a rotary lawnmower.

“Green waste compost” is made in facilities using shredders and turning-machinery, often sold after two months of composting, perhaps less. It reaches a high temperature which gives the black colour, almost charcoal. It’s often delivered hot and if so is best left in a heap, if you have time and space, to finish decomposing. I reckon to order and have it delivered in July, for spreading in November. When it arrives the heap temperature is often 60C/140F, and sometimes the heap needs water as it has dried out by steaming. There are no weed seeds, and nutrient status is low but satisfactory.

Mushroom compost, used for growing mushrooms in undercover benches, has more nutrients than green waste compost and again may be delivered “unripe”, though it can be used at this stage. I prefer to leave it 3-4 months to finish curing. Ingredients are mostly straw and some horse manure. There used to be chalk as well but some mushroom compost does not have this now, my last batch was pH 6.8. Ask your supplier if worried, but I suggest not to worry about the pH because I have never found it to cause problems, even when I used mushroom compost of pH 9.5 on soil of pH 7.8. Don’t believe everything you read about “pH has to be ‘correct’ for different crops”.

Chicken manure is unusual because of it’s high amount of nitrogen. In small amounts, say you have a few chickens, I suggest adding it to the compost heap where it helps other wastes to break down. To use it as mulch, there must have been plenty of bedding such as straw, and all of it needs to have decomposed for 6-8 months in an aerobic heap. Fresh or ‘neat’ chicken droppings are more akin to nitrogen fertiliser than to compost, and best used sparingly. Otherwise growth may be excessively leafy with more pests such as aphids.

Best avoid manures (mainly horse) that have a lot of wood shavings, because they take years to decompose. However a lovely aspect of no dig is that woody mulches on the surface do not cause nitrogen robbery. Instead, problems with wood on beds are (a) the potential for slug habitat, and (b) if you spread compost a year later, the wood is “incorporated”, unless it has decomposed. So small pieces of green wood prunings of deciduous trees are good to use, preferably stacked for a year before spreading, almost compost. Of a high fungal value, the opposite of say chicken manure (bacterial mostly).

Horse manure is at a small risk of contamination by aminopyralid weedkiller, occasionally sprayed on grass for horse-hay. Its the only weedkiller I know which persists, and its lethal to potatoes, tomatoes and legumes, whose growing tips become curled and twisted, see here and elsewhere on this site via the search bar.

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25 thoughts on “Start no dig, soil types, weeds, composts to use

    1. Hi Sharon,
      I am pleased with my Bosch AXT 25 TC, electric and max. diameter 45mm. It’s for woody material, not so good for stems like broad beans. Gives a good material for making compost.

  1. Is it ok to plant into “finished” (no longer hot) mushroom compost or only use as mulch? I’m being told by a supplier that the one here is so N rich it will burn my plants unless mixed into my soil. I don’t want to do that, but it’s very affordable and I want to use it for quick start option 2 for a first time flower bed turned veg garden. I plan in 1-2 weeks to lay thick soaked in water cardboard due to bugleweed groundcover (unless that is not a competitive plant for nutrients?) followed by 4 inches total compost so I can plant by the last frost date 4/20. My base soil is damp clay. Good plan? Less compost to start possible? I plant directly into any finished compost without plant harm? Lastly, thoughts on a 2 yr old zoo brew compost for mulch?
    Forgive my peppering with questions! I’m so eager and trying to be frugal as well. I found your method a month ago and am trying to learn as much as I can. I appreciate all the wealth of knowledge you share so freely!

    1. Hi and thanks Charlene.
      I never saw or experienced the famous root-burn so often alluded to, and find that plants root happily into finished mushroom (and all other) compost.
      Zoo poo is probably good, no experience of it.
      Your plan looks good. If the weather or ground are wet, no need to soak the cardboard.

  2. Hello! Thanks for all the information. I have the cardboard down and am having compost delivered. Seeing as how the compost probably isn’t very high quality (I’m fairly sure it’s mostly green waste), should I do a 50/50 mix of garden soil and compost to make my new beds?

    I also am wondering if I need to put holes in the cardboard under the plantings. I’ll be doing 6″ of compost or a compost and soil mix on top of thick cardboard.

    Hopefully by this fall we’ll have plenty of our own compost to use. I can’t wait to get everything going. Thanks so much!

    1. All sounds fine Sarah and no need for holes in cardboard, roots will go though.
      Even if the compost is not the best, it’s better than soil, which also will be not the best 🙂
      Happy harvests, before too long.

  3. Thank you! Your content is so helpful and generous.
    RE- BRAMBLES , 1/8 of my new allotment was covered in them. I’ve carefully cleared them all, digging out the crown. Is it ok to cut them up with secateurs and then put them in the compost heap? I want to make compost as we clear but I’m worried these might be too thick and the thorns would stay sharp. Thanks again for your clear guidance, I’m new to gardening and very excited to create a no-dig allotment 🙂

    1. Hi Sara, thanks for your encouraging feedback and well done so far.
      The brambles will decompose but may take two years! Still a good mulch, perhaps a thorn or two. Shredding or mowing them is ideal but great you are cutting by hand 🙂

  4. Hi Charles,

    This is my first year of no going no dig.

    I have had mushroom compost delivered for the first time this spring and have created several beds for potatoes and Alderman peas. The compost is well rotted but some straw is visible – none of my potatoes have come up after 3 weeks and my peas really seem to struggle to grow. The diggers on my plot all have strong foliage emerging already. Also my onions and beetroot (multisown and planted out as clumps) in the compost struggle but the ones in my raised bed of multipurpose compost are thriving. Really gutting considering the effort and money put in.

    Having watched your video about growth problems I am concerned this might be weed killer damage…how would I test for this please? Is there anything that can be grown after a while if it is indeed aminopyralid contaminated compost?

    Many thanks,
    Christian

    1. Oh dear this sounds like either the compost was super fresh, maybe hot in the heap at time of spreading? I do advise bout this but it’s hard to be too discouraging or nobody then does anything and most people are getting on alright, perhaps a little slow at first.
      Best of course is to set up autumn before but Covid made that not possible.
      It it’s aminopyralid, peas would show deformed new leaves. I hope not. Hang in there.

  5. Hi Charles,

    I was wondering if this would be a successful approach to use on an area of garden that has become overrun with Crocrosmia and Lysimachia?

    Many thanks.

  6. Hi Charles,
    I love watching your YouTube videos and have leant so much!
    I’ve just ordered a polytunnel and want to start using it straightaway but part of where it will go is lawn. I’m planning to cover the lawn with thick cardboard and then put 10-15cm of mushroom compost on top and plant straight into it – tomatoes, aubergine, peppers etc. Will this be sufficient to ensure the grass doesn’t start coming up through the beds?
    Many thanks

  7. Hi Charles,
    I have a question about the mushroom compost. Can I use it directly after it’s being used for growing mushroom or it needs curing times. If yes, how much time?
    Also, can I just use it as the soil substrate to grow in containers? or I need to mix it with other material.
    Thank you

    1. Hello Amani, yes it’s best aged.
      Depends a little how fresh it is when delivered: often you can see bits of straw, peat, and white mushroom stalks. From there best wait 2-3 months. After that it can be used in a pot, without soil added.

  8. Hi Charles,
    I’ve meet you in Youtube at the beggining of the pandemic and I’m already a big fan!
    I’m starting a no dig garden and I would like your thoughts regarding using compost chicken manure for beds and wood shavings for pathways, please. I have tons of well rotten chicken manure! Also I have a good source of wood shavings. What do you suggest doing with those materials for start a no dig garden? I’m using a landscape fabric to reduce the weeds and I’m saving cardboards to prepare the garden as well. I live in the south of Brazil – Humid Subtropical region – and hope to test no dig method here.
    Thank you!

    1. Hello Elvio
      Well done, sounds good.
      if the manure is pure poo with no bedding like straw, us no more than 2-3cm over the cardboard. Try a small area with more, to see how it grows.
      Cardboard is needed only if many weeds.
      Perhaps look at making compost for use next year, from wood shavings and manure.
      Hope it goes well.

  9. Hi Charles,

    How are you? I was able to attend one of your courses in Feb before Covid! I thought you might help me to prevent my divorce! The other day some tree surgeon were clearing some branches in my neighbour’s garden. I remember you saying “wood chips, not bark” and asked them to give me the chips. As it happens, they can only offload the whole truck, not half of it and now I have literally a ton of wood chip in my front drive. I only have a small kitchen garden at the back of the house and have mulched all the paths with probably like 5/10 cm of what I now know you call ramiel. I still have loads of this fresh wood chips and my partner is about to evict me and the ramiel from the house. Shall I put them on the side next to my compost bin and let them decompose? Shall I get horse manure from nearby field to speed up the process? I’m literally covered in wood chips and don’t know where to put it. I think I got more than I bargained for and apparently it will take years to decompose. I’ve been reading loads and apparently I can’t put them on the actual beds or I will deplete vegetables from nitrogen. Shall I pay for someone to take the chips back? Cheers, sorry to bother you. I’ve read and read and couldn’t think of another trusted brain to pick!

    1. Hi Bea
      Funny message! They will decompose within 18 months to something quite nice, esp if watered now and kept moist.
      Worth hanging onto if you have space. Pile in a neat heap back-of-garden? Under a tree?
      On beds they don’t deplete much N when on top. Problem is more accumulation of woodlice and slugs, difficulties of sow & plant.
      May it all work out for you 🙂

  10. Hi Charles, I’ve really enjoyed watching your YouTube videos and am really keen on using the no-dig method. I’m new to the allotment world and starting with a 3 pole plot. The site has been cut back of weeds – well cut to the ground. Evidence of dandelion, bramble and couch grass. My question is do I just place organic matter 1 – 2 inches on top followed by cardboard mulch and cover with landscape fabric? Do I need to remove anymore of the bramble/weeds? Do I then leave it until Feb/March for sowing /planting the new season veg & fruit. Are there any winter veg I can plant through the mulch during this time?

    1. Sounds fun.
      Brambles’ main stems want levering out – not all the roots.
      Card on top of remaining weeds then compost.
      Not much sowing time left, say spring onions and salads this week

  11. Hi Charles, your channel is the go to place for me, and I appreciate your efforts. I have a small area for veg, and declining body parts dictate raised beds for me. So far, I have applied your no dig technique, without the cardboard, to the top 6-8 inches of these beds with good success. I am now creating two 16 inch beds and have used the bottom reed/mud mixture from my neighbours pond (he has agreed) to half fill the beds. I will cardboard the top half as per your starter video. There is a plethora of peat free organic compost such as you use for the top layer. Can you please recommend one, or if not possible give a bit more detail of the spec. KInds regards, Chris

    1. Hi Chris, a good project.
      No need for cardboard, which is only against existing weeds.
      I can’t recommend composts because they vary so much, even month to month. Sorry.

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