Today’s tutorial is all about how to improve your soil from the very start of cultivating. You might be about to grow in this soil for the very first time, or you might have cleared a vegetable patch for winter. Either way, the techniques in this tutorial are essential for bringing any soil up to scratch.

Double-digging

Double-digging is hard work, but essential for getting nutrients into a new plot. The diagram below shows what you have to do. Layer 1 is your topsoil, layer 2 is your subsoil, and layer 3 is organic garden compost or well-rotted manure.

You must keep the three layers separate at all times. Dig a trench down to layer 2 (two spades deep) at the end of your bed, and place layer one to one side. Then remove layer 2. In its place, fork in layer 1, and place the manure (layer 3) on top. Repeat this process all along the trench, and add the excess soil from removal of layer 2 to your compost heap with plenty of greens and animal manure.

When to improve soil

Between autumn and spring is the best time to do the heavy digging on your soil. If you have thick clay soil, digging in the autumn is best, but if you have sandy soil, you can leave it till the spring. You can never add too much organic matter to the soil, but as a rule it is best to ensure it is well-rotted before you dig it in.

Digging clay soils over in the autumn means you expose the clods to the frosts over the winter, which break down the structure of the soil and leave it easier to cultivate the following year. Digging a heavy soil also frees up the structure simply by exposing it to the air.

Now is the perfect time to double dig any unused or empty beds. Start digging your beds, gradually, from this weekend.

Mulching

Although leaving clay soils exposed is a good idea if you want to break them down, it is usually a poor idea to leave your soil open and exposed over the winter months, as heavy rain will leach away the nutrients you have worked hard to build up.

The best thing to do is to cover your bare soil with a mulch. You can use a black plastic sheet mulch, but the wisest thing to do is to use an organic material that will also add nutrients to the soil. Here are some of the best mulches:

Farmyard manure
Seaweed (although this can start to smell, so be aware of any neighbouring gardens)
Spent mushroom compost (be aware that this makes your soil more alkaline)
Spent hops from a local brewery
Grass clippings
Straw
Coffee grounds
Cocoa shells
Leaf mould
Bracken

You can also cover your soil using a green manure, which we will be looking at tomorrow.

It is best to have a mulch in place from late September onwards, to trap warmth and moisture into the soil.

You can also add mulches to beds that have already been planted in the garden. Do this in late spring once the plants have become established but before the soil dries out. The mulch should be at least 6cm thick to have an effect. Don’t mulch right up to stems and trunks as thic can cause rotting, fungal problems, and suckering in some plants. The exception to this is members of the tomato and potato family, which form adventitious roots from their stems.

Find the most plentiful supply of a material that you can mulch all your bare soil with before the winter, and start covering up now.

Today is a short post because the work involved is so hard. Get digging now. Here are those tasks agin.

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