Have you been wondering why I keep putting cardboard all over my allotment? It isn’t the most conventional of gardening techniques I’ll admit. But there is method in my madness…
Would you rather spend hours digging out weeds and double digging the soil (and then repeating the exercise every three years or so), or would you rather not bother at all and let the worms do all the work? When I decided to take on an allotment, I started doing some research, and came across a method of cultivation called “no dig”. The main proponent of this method in the UK is Charles Dowding, and I am currently reading his book “Organic Gardening the Natural No Dig Way” and following him on social media.
The theory is that the soil has a natural population of bacteria and fungi which form an important element of the health of the soil, and assist the plants in growing. Digging not only disturbs and may destroy this, but you also expose weed seeds which may then germinate (but otherwise would have remained dormant). The worms also get cross (well wouldn’t you, if someone kept digging you up and disturbing your bed/dinner?), and they are vital for soil health. The digging also destroys the soil structure, and can lead to impaction of the soil (whereas what you really need is a nice fine tilth).
With the no dig method all you do, basically, is mulch with organic matter. This can be garden compost, well-rotted manure or bought in compost. The worms, to whom you have served their dinner, will then help to break the mulch down and pull it into the soil. This improves both its structure and its fertility, all the while saving your back and your energy. Because you need to mulch quite thickly, any weeds are starved of light and so die, or don’t germinate in the first place. Even couch grass will, eventually, give up the ghost.
This sounds like a wonderful gardening method to me, and I am keen to have the entire plot (125sqm) run with the no dig method. But… there is always a but isn’t there? I need lots of compost, or well-rotted manure, which I don’t have (without spending lots of money). And I want to grow stuff, this year. I am impatient. So I am doing a combination – digging out the couch grass and mares tail on a slightly less weedy area, whilst trying to get going with the no dig on the rest of it. Hence the cardboard, to cut out the light.
Obviously, cardboard isn’t sufficient, and I still need mulch. I discovered that we have a supply of fresh horse manure on site. I have bought a great big shovel, and now a wheelbarrow (oh so good for lugging tools etc. from the “mobile shed” parked outside, to the plot) so guess what I’m going to be doing next weekend! I am also collecting more cardboard from a local bike shop who have kindly offered me as much as I can use. The fresh manure will be too acidic to grow anything in for now, but it will rot down, as will the cardboard, and then hopefully next year we will have wonderful soil.
If I was scientifically minded enough, I could try and do a comparison in soil quality and productivity between the area I am weeding now, and the areas I am mulching. I suspect that I’m not going to be accurate enough in my gardening to manage that, but I shall attempt some comparisons.
The advantage of digging out all those weeds though has been that I am getting to know my soil. The surface has clearly had lots of organic matter dug in, it’s lovely and dark with a crumbly texture. There seems to be a thin layer of clay almost a foot down, and under that it’s orange sand (apparently there is a ribbon of it running through the area). This means that the plot is well drained – when I visited the other day after lots of rain, I was expecting lots of mud, but the soil was fine. This seems good now of course, but in warmer weather may mean lots of water. And mulching too – which helps to retain moisture. We also have lots and lots of worms (slightly grumpy worms due to having their home disturbed, but they will love me when it’s all done and I give them lots of dinner).
At the weekend I uncovered the area I had previously dug over, only to discover that grass was growing again! Not very much admittedly, but I had already realised that I’d not weeded this area as thoroughly as I’d done the other side, so I did it all over again, and removed a few more buckets of weed roots – and went over an area not previously done. I very nearly finished digging over the area for planting this year, but my arms and back gave out at 5pm on Sunday (after about 12 hours digging and weeding over the weekend). A couple more hours and I will have an area 6m x2.5m ready! As it’s still far too cold to plant anything out, I will mulch this with some bought-in compost (and some organic fertiliser pellets), then cover it with my weed-proof membrane to ensure that the weeds don’t come through again, and to warm the soil ready for planting out in April.
Now, on with more digging, and trying to get the potatoes planted – fingers crossed for some sunshine this weekend!