Five Easy Green Gardening Tips to Make Bad Soil Fertile

How do you grow organic vegetables quickly on soil that's utterly sterile?

A friend once asked me. 'I'm taking out a row of old leylandii trees. What should I add to that awful soil, once they're out, so I can make an organic vegetable garden?'

Her soil was dead. Leylandii, and all other large conifers, deplete the soil absolutely. If she wanted to grow organically, nothing but several tons of rotted horse manure or organic compost would help her now, I said, preferably mixed with sand and old leaves and well rotavated in.

She told me she had no rotavator. So I advised her to toss in anything that might rot down over twelve months, gracefully, and contain or promote soil bacteria. Such as several barrelfuls of raw kitchen waste from a local bar or restaurant, plus good topsoil and rough compost, if she could get it free. Then buy some worms from an angling shop and scatter them on the soil, I advised her.

She told me she didn't like worms. So I suggested: 'Sow a green manure, plants with nitrogen-fixing properties like broad beans. When the plants crops, dig them all in.'

Another idea, I said, was to create Open Compost Bins. 'Dig a trench, and throw in all your kitchen waste. When the trench fills up, dig another one beside it, and start again. You'll have organic compost in no time. Rotate these trenches around the patch.'

In fact, that's an excellent idea in a vegetable garden, even if your soil is good. 'As each trench matures,' I said 'turn it and plant a few chitted (pre-germinated) potatoes in it. Even better, sow collards. They'll grow anywhere and can subsequently be tilled in as green manure.'

'I don't like digging,' my friend replied. Another friend came to her rescue. 'Broadcast-sow a low-growing pea crop, early in the season,' he said. 'Any peas that grow just two foot or so high will do. They'll support each other as they grow, so there's no need to trellis. Not only will you have a nice green manure crop, but you'll also be able to pick a food crop from it.

'When you're tired of picking, rake the plant matter into the ground. Then at once broadcast-sow bush beans. The nitrogen left by the peas will jump-start them to a good growth. Pick those beans and eat them! Then rake the vines into the soil. More green manure. The soil should now be greatly improved and you may still have time to plant an autumn crop of brassica, garlic and other over-wintering crops in it.'

She said: 'I don't care for beans.'

Undeterred, he advised my leylandii-afflicted member to do a Soil Test. Fir trees not only deplete all soil nutrients. Their dropped leaves also make the soil hideously acidic. A Soil Test would tell her just how bad her soil was, he said, and in what ways.

Fortunately, lime or wood ash can quickly correct an acid soil. It's a lot easier to make a soil more alkaline than to make it more acidic. But if you must make a soil more acidic - for example, to grow strawberries, potatoes or heathers - one green gardening tip is to plough in conifer needles like leylandii. A lot of them. Then wait three years.

My leylandii sufferer did not report back on all that good advice. A lady so averse to worms, rotatavators, digging and beans sure had a big challenge ahead of her, I thought. But when I visited her garden a year later, I could see no leylandii. Just lots of healthy-looking organic vegetables. So I guess the advice had worked.

Dr John Yeoman PhD is founder of the centre for natural gardening ideas, the Gardening Guild. For a free big 6000-word ebook Lazy Secrets for Natural Gardening Success, go to: http://www.gardeningguild.org/lazy