Gardening: Trench warfare in the heart of Essex

workshop

How do you make a feature out of a ditch? In her regular advice column Anna Pavord comes to the rescue of the Cooper family.

We moved to this much smaller house 18 months ago, simply to gain a bigger garden. The garden is a strange shape, not very long, but extremely wide. Our longest boundary is a ditch about 4ft deep. You could call it a stream if you felt ambitious. I have strong ideas for most of the garden, but the ditch stumps me. At the moment the banks are covered in about 80 per cent nettles. The other side of the ditch is open farmland, with several mature trees.

I have considered a fairly wild and natural look (minus the nettles), but I also like the thought of large-leaved plants such as gunnera and castor oil plants making a tunnel for the children to explore. My main concern is that the ditch dries up in the summer, and I have no idea what plants, if any, will stand being very wet all winter and dry all summer. I also feel that I may have to work in a small area at a time, replanting as soon as I have got rid of the nettles. In some places, where I have tried spraying off the nettles with glyphosate and digging them up, the stream banks have eroded. Can you give us some advice?

Eve Cooper, aged 36, moved last year with her husband, Paul, and their three boys to a brick-built cottage, the middle one of a terrace of three overlooking farmland in the flat, rich countryside near Saffron Walden in Essex. Their garden spreads wide behind all three cottages, bounded by the problematical ditch. There are about 63 yards of it, curving round the boundary. Ditches are made for a reason, and any planting would have to take account of the fact that the area might be submerged. My feeling, though, looking at the amount of leaf litter that had accumulated along the bottom of this ditch, was that it was much drier now than it had been in the years after it was made, at least a century ago.

Because the ditch represented the buffer zone between garden and landscape, the planting needed to be sympathetic to both - a kind of transition zone. It was impractical to garden the whole 63 yards intensively, but the area naturally fell into three different territories.

About halfway along the boundary, where it faced the back of the cottage, Ms Cooper had made a long flowerbed butting on to the ditch's top edge. The ditch behind could make a backdrop for the bed, filled with gardenesque plants such as gunnera, rheum with tall spires of rhubarb flowers, purplish- leaved eupatorium, filipendula, shaggy-flowered inula, and ligularias. A powerful physique is what she should look for in her "ditch" plants, heavyweights that she can leave to slug it out for 10 rounds against resurgent nettles and other undergrowth.

The sections either side of this central zone could be wilder in style, planted with alder, elder, willow, dogwood and other plants to echo the mood set by the few remnants of native trees and shrubs. A willow and a big field maple grow there, both pollarded, and blackthorn, wild cherry and sycamore.

On the left-hand side of the central area, where the ditch curves past the Coopers' newly planted orchard, I would thicken up the boundary on the far side of the ditch with trees such as the cut-leaf alder, Alnus incana 'Laciniata'. This survives manfully in areas that are both cold and wet. As the ditch follows the east boundary of the garden, more cover and shelter would be welcome in winter. The cut-leaf alder, with foliage deeply divided into toothed lobes, would meld imperceptibly with the true natives, but at the same time would have half its heart in the garden it faced.

More willows would work well along the far boundary, too, as much for the cheering sight of their winter twigs as their elegant summer foliage. I'd continue to pollard them, once they were big enough to take it. It is a traditional technique, and the bark on the new growth produced as a result of the cutting back has a much brighter colour than old wood. Salix alba 'Britzensis' is one of the best, with orange stems glowing deeper and richer as winter days get colder and bleaker.

But how are the plants to be got into the ground, given the present thick blanket of nettle? And where exactly should they be planted? Not at the very bottom of the ditch. That should be left clear, for winter water (if it comes) and for Jo (11), Ben (eight) and Charlie (two) to take over if they want, in summer. One of the reasons the Coopers decided last year to move their family from their tidy house in Cambridge was to give them the kind of wild, free, country childhood that Eve Cooper had herself.

City-born Paul Cooper is not into gardening, but he had the inspirational idea of giving eight hours' worth of a man with a spade to his wife as a birthday present. The best present she's ever had, says Eve Cooper. She's the greatest digaholic I've ever encountered, and had already dug by hand the entire area where the fruit trees (another birthday present) are now planted.

But digging is not the answer in the steep-sided terrain of the ditch. On the far side, strimming round the existing trees would reveal enough of the lie of the land to plant alders and willows. If the Coopers planted standard trees, on 4-ft stems, their heads (trees', not Coopers') would already be above the danger zone.

On the nearside bank, the weedkiller glyphosate will eventually control the nettles, but the bank will erode if Eve Cooper then tries to pull out the roots. Easier to leave them be, dig out planting holes where they are needed and mulch the rest of the area with grass cuttings, or fairly coarse woodchip mulch, that won't slide immediately down the bank.

She's right in thinking she should tackle one patch at a time. This is how I gradually brought the bank in our garden under control, although it took me 12 years. The weeds need to be properly killed before you plant and I found that not digging was the key. If you dig, you bring a whole new seed-bank of weed to the surface. You also destabilise the soil. If the areas either side of the central area were treated as "wild" areas, then plantings of shrubs such as dogwoods, fancy-leaved elders and shrubby willows would be entirely appropriate.

It will probably take the whole of next year to get on top of the nettles but by this time next year, Ms Cooper could be planting dogwoods such as Cornus alba 'Elegantissima', the lovely, purplish-brown- stemmed shrubby willow Salix hastata 'Wehrhahnii' and the elegant elder Sambucus nigra laciniata. The willow has wonderful woolly white catkins; the elder has the wide, white flowerheads of the hedgerow elder, but leaves 100 times more handsome. While these areas are getting established, Ms Cooper can be making lists of plants for the grand slam central area which should be lush, jungly and composed mainly of plants with good leaves. The biggest plants, such as gunnera, should be planted towards the bottom of the ditch; smaller ones, such as hostas and rodgersias, towards the top.

A trip to the canal garden at Beth Chatto's home would give her an idea of what is possible: huge-leaved hostas, rodgersias with leaves like enormous horse chestnuts, big, tough clumps of day lilies, Hemerocallis, flag irises and cabbagey clumps of the daisy-flowered Senecio smithii. Perhaps Paul Cooper might arrange a visit for his wife's next birthday present.

Beth Chatto Gardens, Elmstead Market, Colchester, Essex: open in winter, Mon-Fri, 9am-4pm, admission pounds 2.50.