Heaps of goodness In praise of homemade compost

THE compost bin scarcely has enough room for all the veg bed, herbaceous border and hedge clippings just now. But the resulting compost is far too precious for you to cart all this material off for council recycling. It will nourish the soil and give you a bigger harvest next year.

I’m not the only one singing the praises of homemade compost. A meta-analysis of 690 worldwide studies was published this year in Soil Biology and Biochemistry.

The findings, by Luo et al, were staggering. They showed that crop yields were, on average, 27 per cent higher on ground that had been enriched by organic materials compared with mineral-only fertilisers.

Five types of organic material were trialled: farmyard manure (FYM), compost, straw, green manure and solid waste. FYM increased yields by 49%, with compost second best at 17%.

As you would expect, these are broad averages and results varied depending on individual crops and types of soil. Clay did best, clay-loam next, with thin sandy ground taking its usual third place.

Extra enzyme and microbial activity in organic material let the soil absorb nutrients more effectively. So, even if you can’t lay your hands on FYM, make as much compost as possible.

If your compost bin overflows, make space by removing partly composted, rough material and spread it on any cleared beds. These compostables initially act as mulch and, as they break down and are absorbed into the soil, they improve its structure.

It’s best to add compost to the ground while plants are growing in the spring, so if you have enough space, buy or build a new compost bin instead.

A small inexpensive electric shredder deals with thinnish woody stems, such as raspberry canes and currant branches. But you could always use loppers and secateurs to reduce a small branch to a heap of 1-2cm sticks. After starting to break down in your composter, they’ll finish the process on the open ground.

Fresh green herbaceous prunings are easy to break up and a mountain of hedge trimmings can almost disappear. Use a rotary mower to shrink a large pile to half a grassbox. Thinly spread the prunings on the grass or slabs, set the mower high and lower onto the heap.

Go over the heap till you’ve collected it all up. You’ll end up with a fine mix of green leafy and browner stalky stuff. It injects nearly as much heat to the compost bin as fresh grass clippings.

Treat veg clearings in the same way. A huge pile of runner bean

vines or giant courgette plants soon shrink before your eyes. And, like grass, this greenery blasts heat through the bin.

Prickly rose and gooseberry prunings are more difficult as the thorns may seek out your blood in the spring.

After reducing your heap, spread it as mulch underneath a rose hedge or shrub – wherever you won’t be walking.

If you have enough space, you could build a “dead hedge” for everything (see my website for details).

When emptying pots, separate plants and spent compost, putting plant material in the composter, and using the spent compost as mulch or to fill dunts in the lawn. Don’t try to compost it: it is inert material that can’t rot down, and it cools the bin without adding any goodness.

And finally, look out for anything you could recycle in the garden. Use straight poles instead of bamboo canes. Fan-shaped branches make good plant supports.

Put a likely-looking one aside and cut to support any plants next year.

It’s all free and is much more environmentally-friendly than most products you’ll buy.

It is best to add compost to the ground while plants are growing in the spring