EARTH AS NATURE intended is hard-packed, inhospitable stuff, crammed with nasty stones. Earth as builders intended will also contain half-bricks and chunks of concrete. Tender little plants don't appreciate anything but soft, aerated loam. So new borders must be prepared with all the care exercised by parents fitting out the nursery for their first-born child.

This involves digging out the soil, sieving it to remove detritus, and replacing the resulting plant-friendly granules, plus a good helping of delicious, nutritious compost. But the first, essential step is to book an appointment with the osteopath; while sieving and mixing may sound akin to cake-baking, it is in fact back-breaking.

Garden sieves are enormous things like gold prospectors' pans; enthusiastically filling them to the brim with earth makes them far too heavy to lift. One spadeful at a time is quite sufficient to deal with for anyone who is not an Olympic-standard weight-lifter. This means slow going; a border that will shelter a few measly shrubs takes on the proportions of a half- acre field when it's gone over by hand. Strange things come to light - chunks of broken crockery always, mysterious bits of plastic usually, sinister quasi-human bones frequently, priceless prehistoric artifacts and long-lost diamond rings almost never. Working tidily is painfully slow, but sieving enthusiastically means a fine haze of dust rises up into the hair, eyes, etc of siever (who can expect to sneeze dirt particles for some days afterwards).

Once the border is done, it looks so appealing - all lovely, squidgy brown loam, neat and empty - it's quite distressing to actually mess it up with lots of untidy, sprawly plants (though in fact it returns to its original hard-packed look as soon as it's rained on for the first time). And then there remains the question of how to dispose of the half-ton of rubble extracted. Dustmen are highly suspicious of bin-bags full of stones. Adding a single handful or half-brick at a time to the kitchen bin each time it's emptied disguises heavy-duty debris very effectively.