Improve the Soil in Your Organic Veg Garden

It is all about the soil.

When it’s in good shape our plants will have all they need to get on with the business of growing. This is especially true when we plan to load our plates with the fruits of the garden.

Acid or alkaline soil?

The starting point with a new piece of ground is to find out how ‘acid’ or ‘alkaline’ it is. A pH meter shows how ‘acid’ or ‘alkaline’ it is by measuring the percentage of Hydrogen ions in the soil on a scale from 1 to 14. Most crops, with the exception of potatoes, need a ‘neutral’ soil with a pH of 7 or just a little less. If the soil is in the range 4½ – 6, and you want to grow vegetables, you should add ground limestone, remembering that it takes a few months for the pH level to change. This means that lime should be added in the autumn. So, if you’ve missed the boat for this year, don’t worry, you will get a crop and can aim for a better one next year! [You reduce the pH, say for growing cranberries, by adding sulphur chips.


Thin soil

The soil’s structure can’t be ignored either. You could be lucky enough to have fine crumbly loam, or you might have thin, gritty soil. By gradually adding home made compost, well rotted muck and green manures you’ll build up a soil good enough to eat! But this won’t happen overnight.


Clay soil

At the opposite end of the scale, thick, impenetrable clay will make a marble when you rub it in your hands. In this case, you need to break up the clay by using a similar recipe as for my soil. Its optimum structure is 50% soil particles: 50% air, so we have to add biodegradable matter either to bulk up a thin soil or break up a clay one. With a new house, the garden can often be riddled with clay, pale yellow or blue/grey. This subsoil will have been disturbed and brought to the surface when the house was being built. If the worst comes to the worst, you’ll have to import top soil from a builders’ merchant. In that case, be sure to inspect it as the quality can vary enormously. If it’s very thin and stony or claggy with these horrible little parts of blue-grey subsoil, avoid it like the plague. Browny, black, crumbly earth is what you want.



Earthworms play a vital part in improving the soil’s structure by aerating it as they break down decaying vegetation and transform it into rich wormcast. Darwin estimated that over one year worms could produce 10 tons of wormcast in one acre of ground. So ‘no dig’ gardeners will argue that you should put a layer of compost or well rotted muck on the ground in autumn, cover it with a membrane and let the worms do their bit to produce airy, rich earth. This sounds great, but what about all the slugs, slug eggs and root nibbling millipedes that also enjoy sheltering there, ready to wreak havoc in the spring? Give me a spade any day!