How to clear ground and cultivate a vegetable plot from scratch
The initial tidy-up
Before you tackle nature, you may well have to deal with man-made problems. A neglected garden or allotment might contain general building waste, half-empty paint tins, old carpet, a dilapidated shed or greenhouse, bottles of garden chemicals and all manner of scrap timber and metal which at one time was used as plant supports, sides of vegetable beds etc. Your first job will be to remove all this rubbish. On an allotment site you are in effect a tenant, so it is worth asking the landowner if they will help with any waste disposal. Councils in particular can often be pressed to clear-up the plots they rent out. Otherwise, depending on the scale of the problem, this might involve a trip or two to your local waste disposal site.One thing to remember is that not all waste is visible – artificial materials like carpet can contain a variety of toxins including dyes, glues and preservatives such as cancer-causing formaldehyde. While the direct risk to your health is likely to be low, and the weather will break down many harmful compounds, you may prefer to remove the topsoil immediately around such rubbish and grow your first few crops in another part of the plot.
Dealing with weeds
Weeds come in all shapes and sizes, each with their own characteristics and problems, but for simplicity they can generally be divided into two groups:- Annual weeds grow from seed to maturity, reproducing and setting new seeds, all within one season. This means they spread rapidly (often blown on the wind) and can quickly colonise even sterile soil. The good thing about them is they are easy to kill (usually by hand weeding and hoeing), and if you hit the population hard enough they will soon be under control. The trick is to pull them up as soon as you see them, before they have a chance to reproduce. As the old saying goes; “One year's seeds means seven years' weeds”.
- Perennial weeds are harder to deal with. They are longer-lived plants, which survive most winter weather intact. Worse still, they can often spread vegetatively (which means even a tiny piece of root left in the soil can re-grow into a whole new plant) as well as by seed. They need to be thoroughly dug out, and they may grow back many times before you kill them off. Some, such as horsetail and ground elder, are almost impossible to get rid of completely, so keeping them under control is the best you can do.
- Attack: The first stage is literally a physical assault on the unwanted plants. It is possible to clear ground with a hand scythe or a pair of loppers, but this is a slow process and will take hours of very hard work (not to mention blisters), especially if you have a lot of ground to cover. Petrol driven strimmers can be very noisy, but for a situation such as this they will greatly reduce your initial workload and are a much greener option than weed killer. Heavy-duty brush cutters are available to rent from most tool hire centres and will save your back as well as your patience. Choose a metal-bladed version rather than nylon, as the latter will probably snap when faced with dense brambles.
- Burn: This doesn’t refer to the remaining ground cover but rather the weeds you have already cut down. Rake up the debris and have a bonfire, or invest in an incinerator. Perennial weeds are not easy to compost successfully (they often grow back when you apply the compost), so it is better to be on the safe side and destroy them thoroughly. The ash produced can be recycled as a good soil improver.
- Cover: The easiest part of the process comes next: applying a cover. Depriving weeds of light and moisture will kill or at least dramatically weaken them. A sheet of opaque, heavy black plastic will smother them efficiently, but this must be left in place for a least three months - ideally over winter, when the ground can't be used for much else. Damp-proof membrane from a builders' merchant is just the job, and it is not expensive . You'll need to weigh the plastic down very thoroughly as it can float away like a sail in a strong wind. For an alternative solution, use empty compost bags filled up in-situ with damp soil.
- Dig: Lastly, reach for the garden spade and fork! The dig is an important part of preparing ground for growing and, while it is time-consuming, it will dramatically reduce weed re-growth. The other important effect of digging is that it opens up the structure of the soil, allowing better drainage, root growth and nutrient availability. There are several techniques to choose from, and you will need to assess the condition of your soil (see our Soil Types GrowGuide) before deciding on the best course of action. The most common of these is double-digging...
Double Digging
Double digging is the traditional approach to opening new vegetable beds. It will greatly improve heavy, compacted or nutrient-poor soils. The name refers to the method of removing one layer of topsoil so that the next layer can be broken up. This is hard work, but with good management should only be required once in the life of your plot, particularly if you define clear paths so that the soil is never compacted by being walked on.- Start by making a narrow trench along one end of the bed, roughly the width and depth of the head of your spade (see the photograph above). Move the soil into a wheelbarrow to be used later.
- When the first trench is complete, add a 10cm (4in)-thick layer of well rotted compost and use your fork to break up the bottom of the trench, working the compost into the soil.
- Turn the second 'row' of soil over into the first trench and break it up thoroughly, removing weeds and stones. Fork compost into the new trench as before, and continue backwards across the bed.
- When you reach the end of the bed you will be left with a final trench and no more ground to turn over. Simply use the soil in the wheelbarrow to fill this after you have added the compost and the job is done.
Lastly
If you are not using the newly-prepared area straight away, cover it with permeable black plastic or sheet cardboard to keep it weed-free. In previously uncultivated areas, vast numbers of annual weed seeds can be blown onto your freshly prepared plot and undo much of your hard work in a few weeks.Alternative Approaches
If digging over the entire plot seems like an impossible amount of work then there are alternative approaches, such as building raised beds directly onto uncultivated ground and filling them with large amounts of compost or sterilised top-soil. For smaller areas this can work well and the vegetation that is buried beneath the new beds will simply rot down over time. Perennial weeds will still come up but can be weeded out as with a traditionally prepared plot. Details of the ‘no-dig’ and raised bed methods are covered in our Planting Systems GrowGuide.For others the prospect of laborious digging prompts them to opt for a mechanical solution. Opinion has long been divided over the use of rotavators. In one camp are those who believe they save the time and effort wasted on bashing the ground about with a fork. In fervent opposition are those who believe mechanical cultivation actually damages the soil structure, compacting the subsoil, scattering perennial weeds and killing beneficial worms.
Whilst the blades may not reach far enough down to properly cultivate virgin soil, a rotavator can prove useful in breaking up heavy topsoil between seasons and combining a top dressing of compost with the soil. However, you shouldn’t use one if you still have perennial weeds in the ground.
Summary
- When it comes to weeding your plot, do the job thoroughly and don't cut corners.
- Don't try to clear too large an area in one go. It is better to be thorough than quick and you can always cover part of your plot to be cleared at a later stage.
- Assess your soil before you start to dig to find out which areas need enriching with compost or breaking up by digging.
- Although time-consuming, manual clearing will always give the best result.
- Establish clear paths or raised beds so that the growing area is not compacted by being walked on.
- Cover prepared areas if they are not to be used straight away.
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