The popularity of soil cultivation, and the common conviction that digging is absolutely necessary to grow vegetables and many other plants, shows how habits can become powerfully ingrained. Let us ask what digging and rotovating are supposed to do:
• loosen the soil so that roots can more easily travel through as plants grow
• incorporate manures and compost
• remove and / or bury weeds to clean the soil
• create a tilth for sowing.
I now consider each point in turn from the perspective of a confirmed, long standing no-digger, who finds these arguments very puzzling and somewhat contradictory, as well as causing some damage to the soil.
Soil loosening
If your soil really is so hard that plant roots cannot penetrate, then something has gone so badly wrong that mere digging will probably be a temporary solution. It would be more productive to ask: Why is my soil so hard?
A possible answer could be that you live in a new house and the garden was recently a building site, so that it is full of rubble underneath and has some dubious topsoil above. The clear solution in this case is to import a large quantity of compost – up to 15cm (6") initially – which will serve to create a much softer, more fertile, lively and true topsoil above the existing topsoil, which should probably have been classed as subsoil anyway. The word ‘topsoil’ is often inaccurate and much of it is pretty dead, for instance if it has been kept for too long in a heap so that worms have disappeared. Soil is not a commodity that can be stacked, stored and shipped around. Soil can also suffer from being walked on in wet weather – a sound reason for having permanent beds and pathways.
It is worms and their lively allies in a living soil who are going to do your digging, on a permanent and ongoing basis, far more thoroughly and productively than any spading or forking can achieve. Worms need food: normally decaying organic matter which they turn into humus, another name for which is ‘black gold’ because it is the source of all that is best in plant growth. Even the worst soils have a few worms in there somewhere, so annual mulches of 5cm (2") of compost above them will provide the cool, dark, moist humus-potential that they thrive in and on. Quite soon your worm population will be increasing, and plants will start to grow – including weeds, but they should be easy to pull out of the crumbly compost.
Be aware that we are talking reasonably long-term here. Results in the first season of using compost on very poor subsoil may be only fair, yet all the time you are building for the future. Each year’s crops are an increasingly interesting dividend while the real wealth is in your soil, a balance of health and fertility that increases all the time.
In terms of fertility, chemical farmers and gardeners tend to concentrate on the requirements of individual plants. One encounters phrases such as ‘potatoes are heavy feeders’. Sometimes this can become complicated, as conventional wisdom dictates a different ‘feeding regime’ for each kind of vegetable. Things are much simpler for a composting no-digger, who is simply looking all the time to improve the soil and holds an understanding that well-structured, undisturbed soil has a balance of possibilities that will serve any crop. ‘Feed the soil, not the plant’ is another way of looking at it.
Incorporating manure or compost
Do we need to ‘incorporate’ our compost or animal manure or whatever organic addition we are bringing to the garden? Twenty-eight years of not doing so, on a range of soils and in different conditions, convinces me that there is absolutely no need to ‘dig manures in’ as so many gardeners do, and advise others to do, taking it for granted that it is automatically right and makes perfect sense.
In fact it makes little sense, and I find that results are better from surface application, since that is how nature works. Falling leaves are pulled in by worms, as are many other pieces of surface debris. Charles Darwin describes the worms’ approach quite beautifully in his 1882 book The Formation of Vegetable Mould Through the Action of Worms, with Observations of Their Habits, where he comes to the conclusion that earthworms add between 2.5-5cm (1-2") of topsoil a year in healthy pasture, as they secrete their fertile ‘casts’ at surface level. This is one reason why archaeologists have to dig so deep.
I find that quite soon after applying a 2.5-5cm (1-2") dressing of wellrotted manure or compost on top of the soil, it starts, quite simply, to disappear. Usually within a few months it is all gone and the soil is visible again, only a little darker, more friable and richer, with many crumbly and humus-rich worm casts. That is what we are aiming for, so compost can be applied two or three months before sowing or planting, and will be sufficiently broken up or dispersed or will have disappeared into the soil when our seeds or plants are ready. The soil will be thoroughly ready to receive them.
Occasionally, if time is short, plants can be set into recently composted soil, as long as the compost is not too rough; otherwise there is a risk of slug damage from the slimy beasts hiding under large lumps of half-decayed compost. Any lumpy compost tends to break down best on top of soil rather than being left in a heap, so it is best spread in late autumn or winter, well before planting time.
The other significant danger from digging manures or compost into the soil is ‘nitrogen robbery’. Think of the woodier, tougher, fibrous bits of compost as rich in carbon and needing nitrogen to break down into humus. On top they do this quite slowly, helped by the weather, but inside the soil they are known to use the surrounding soil nutrients, which would otherwise be available to plants, to finish their rotting down. Hence a golden piece of advice is to NEVER dig sawdust into the soil. Its large surface area of wood can absorb huge amounts of plant food. However, on the surface it rots more slowly, mostly where it touches the soil surface, and the problem of nitrogen robbery does not arise. Ultimately, after a year or two of weather ing on the surface, it turns much darker in colour and becomes a valuable plant food. So in many ways it is safer to apply our goodies on top, just as happens in nature, when man is not digging or ploughing.
Burying weeds?
Farmers plough to bury surface weeds and residues, as much as to ‘open’ the soil, although some opening is certainly necessary after tonnes of tractor and machinery have passed over the soil. However, in our gardens there is no heavy machinery apart from a wheelbarrow! Keeping this and our own footfall to restricted pathways will solve any potential compaction problems. But what about weeds and grass?
The answer is to not let them grow in the first place. This requires an extra degree of commitment, especially in the winter half of the year, but has SO many benefits that it is at least worth careful consideration.
The main point is simple: no weeds growing means no weeds seeding. Yet how often does one see, in late autumn and winter, the gardener turn his or her back on their plot, while grasses, chickweed, groundsel and bitter cress are happily growing, then flowering and shedding seed, leading to many difficulties and discouragements in the spring.
One year’s seeding is seven years’ weeding. No maxim is truer or more forceful. One groundsel plant can yield hundreds of fluffy little seeds over a wide area, and a hundred groundsel weeds is not a pleasant problem to deal with. It can be quite difficult to catch all of them before they seed. Meanwhile there are other seeds lying dormant for up to seven years, waiting to spring up at unexpected moments.
Weeding is mostly a great waste of time and stops us doing the fun bits, as well as causing disturbance to the soil as we dig them out or hoe them off.
So act preventively: a stitch in time saves about ninety-nine. Do occasional weeding through the darker months, removing that occasional small clump of grass, chickweed, bittercress or anything except the flowers and vegetables that you sowed or planted. Then nothing has time to seed, because you get to it before that could happen, and in springtime the soil is clean of weeds, which are not therefore offering shelter to slugs, and is ready for immediate sowing or planting, into the free tilth provided by Jack Frost.
Tilth
Here we confront the last fallacy of ‘reasons for digging’. Tilth means a crumbly soil surface, suitable for ‘drawing out a drill’ to sow seeds into, with lots of fine particles that small seeds can nestle into as they moisturise and then send out those first fragile roots.
Diggers and rotovators sometimes spend a long time knocking the soil around to make their tilth, because they destroyed or buried it in the first place through digging or rotovating. Large lumps of less crumbly soil have been brought up to the surface and need time and weathering, or application of mechanical force, to be broken down. In a dry spring, the lumps can go hard before disintegrating; meanwhile a lot of moisture is lost, as well as precious time.
On the other hand, a no-digger can step out into the first mild weather after frost has lifted, to rejoice in a wonderful soft surface that is crying out for seeds or plants. This is particularly apparent if a bed system has been adopted, whereby all squashing of wet soil in the winter is confined to defined pathways, leaving the much larger growing area soft and friable (see Chapter 2). No moisture is lost to cultivation, and there is even another bonus: fewer weeds.
If we return to the logic of seven years’ weeds from one year’s weed seeds, it can be surmised that digging (and rotovating) is incorporating quite a few more seeds each year, with the honourable exception of those diggers who do not let their weeds go to seed. At the same time, in moving soil up and down, a previously buried cache of weed seeds is brought to the surface and exposed to the daylight that is their trigger for germination – unless cultivation is done at night!
Weeds are healers after the digging
I have also come to conclude from watching what happens when I have been obliged to disturb soil, for example to remove tree roots or dig potatoes, that weed germination is almost a defensive reaction by the soil, to remedy the uncomfortable distortions caused by inversions of different layers of soil life and the breaking, even destruction, of some of its existing structure. Weeds are attempting to cover up the pain and heal the wounds. We really can treat the soil, our planet’s skin and source of all our food, better than this.
So, apart from the processes of setting up your garden, please don’t dig! This book is littered with advice to help adjust to a zero-cultivation approach, and once you get the hang of it you will find new alternatives to many ‘traditional’ gardening techniques.
Green manures
This is a good moment to mention an oft-quoted axiom of organic gardening, which is manuring the soil through digging in a green crop grown to increase soil life and organic matter. The aim is good, but I rarely do it because of the digging.
One exception is a crop such as mustard, which is killed by moderate frost. If sown late August or early September it will be just flowering as winter arrives, full of leaf and about 90cm (3') high. After being killed by frost, it will turn to inert organic matter and be taken in by worms so that, come spring, only some strawy stems will be apparent on the soil surface. It has enriched the soil without any digging, but that brings me to the other difficulty with green manures – I rarely have room for them! Any ground cleared over the summer is quickly re-planted with fast-growing vegetables such as beetroot, French beans and salads for autumn and winter.
Perhaps it depends how large your garden is, relative to what you want from it. Mine seems too small, and that is a good feeling to have, ensuring that beds are covered with crops through a long growing season. Other gardens have spare space that is growing weeds, and, while weeds are a valuable green manure in themselves, we do not want their seeds as well – and it is extremely difficult to have one without the other.
So if you are likely to have an unused patch of vegetable or other garden for more than two months of the growing season, it is worth sowing a ‘catch crop’ such as mustard, or a longer-term crop such as broad or field beans, both to prevent weed growth and to enrich the soil. Beans can be removed without digging, or left on the surface for their leaves to rot in, after which the stems can be composted.
See Appendix 1 for the results of a dig/no-dig experiment at Lower Farm, Somerset. This experiment is pictured in the first colour section, pages 6-8.