Dig in and enjoy the pleasure of growing your own compost

The delivery arrived in April and I left it alone in its thick plastic bags.

Eight months later, the top few inches had turned into a lovely dark, crumbly, odourless material that I was happy to handle. Two inches below, it was a dense, wet, sloppy, oozing pale brown mass with pockets of lively red manure worms and smelling not offensive, but a wee bit pungent.

This stuff had been suffocating, fermenting anaerobically in the plastic bags, while air getting into the very top layer had allowed various microbes to do a fabulous job of composting the dung. It all made sense after talking to an old college friend, the lovely "Dr Science".

I'd been planning to manure my soil more regularly - feed the soil not the plants as they say. My allotment plot has relied on the occasional bag of shop-bought compost, and the odd bit of composted material, but it deserved more care.

So, a pH test was done and samples from several locations were all slightly alkaline. Manure decomposes to humus which improves the soil structure and feeds the soil fauna that keeps soil healthy.

Manure can also help adjust the soil pH to neutral, allowing soil minerals and micro-organisms to do a better job.

What to do with it now? Some say apply manure over winter, others say in spring before planting. Both are true. The freeze-thaw action of frost will physically break down the clumps of raw manure - by raw I don't mean fresh from the animal, just manure that is obviously "manure" - and the warmth of spring then does the full composting job.

But uncomposted manure contains highly soluble nutrients which, if applied in winter, can be leached away by rain. Applied in the growing season and the excess of nitrogen released can burn the plants or cause weak but excessive green foliage.

Fully-composted manure - the lovely dark, crumbly stuff - can be applied two to four weeks before planting. It has a higher humus content than manure, it's easier to spread as the bulk will have reduced by half, the nitrogen has changed to the slow release type that feeds plants gently and the heat from the composting process may even have killed off weed seeds.

Composted manure applied over winter will still condition the soil, but may have lost many of its nutrients by planting time.

So being as there is never one way to do things on an allotment, two of my beds have now received an over-winter application of non-composted manure. One bag I've spiked generously with a fork to encourage aerobic decomposition and four bags I have piled in a corner, protected from the rain, with the intention I turn and aerate the pile to help the composting process.

Much of the pleasure of growing your own is just seeing what eventually happens.

• Lorraine Corbett, from Leith, has been a plot holder at the Ferry Road Allotments for nine years.