So, are the colours sublime ...

Fabulous fun or silly affectation? David Stuart and, below, Jane Jakeman clash over the herbaceous border

American friends rabbit on so about wonderful English gardens. As if every semi and bungalow in the land sheltered prettily behind its own mini-Sissinghurst. They should lift their eyes from the brochures and look.

Of course, every semi or bungalow (let alone every cottage, farm and manor) could, indeed, do that. But their owners all think that herbaceous borders are impossibly hard work, and so they put down yet more gravel, or colour-the-year-round. Ugh. Borders are fabulous fun; they don't have to be a hundred yards long, and don't need a head gardener.

The smallest area to make a real effect is about 20 feet long by 10 deep. And they are called borders, not beds, for a reason. They look terrible as isolated island beds, set in a bald lawn. They need a backing, whether of wall, high creeper-covered fence, or hedge. They also look best contrasted with straight edges, paths, even emphasised with box hedging. A herbaceous border with a wavy leading edge will merely make you seasick. I've seen, though, handsome borders with shaggy apple trees, planted each side of a decidedly winding grass path through an erstwhile orchard.

Best of all, you don't need the precious and the rare to make a marvellous border. What you do need is luxuriant growth, and whatever colour mix you like: post-Jekyll, post-Modern, even post-taste.

One of the best borders I know contains entirely seed-grown flowers, and a few rarer plants bulked up over the years. So buy a dozen packets of seed now: oriental poppies (some good pinks and whites, as well as the well-known scarlets), lupins, aquilegias, campanulas (all "musts", especially Campanula persicifolia, C trachelium, and C lactiflora), delphiniums, penstemons, catmints, rudbeckias, and heleniums.

Don't ignore foliage and green architecture. Linear foliage is an especially useful contrast. Bearded irises don't like the competition, but Iris sibirica variants, I pseudacorus (especially the wonderful pale `Bastardii'), and even, for the front, black forms of I chrysographes, all look great and do well.

But there are marvellous grasses, red hot pokers, the wonderful St Bruno's lily, real lilies, and on and on. Huge thistle foliage, as jagged as possible, is good, too, whether from acanthus, onopordum, or cardoon and artichoke.

Don't fuss too much about achieving a careful gradation of heights; you don't want the border as carefully cambered as a cycle racetrack. Do put big delphiniums at the back though; if they fall over no one will see.

As with most human activities, it's easy to make a passing show, much harder to make a top-notcher. Talent will out. However, there are some "easy mixes". If you need the border to start early, use pink poppies, cream and white lupins, deep red Chrysanthemum coccineum, masses of white and blue campanulas. Add catmint as desired. If you yawn at the marvellous `Six Hills', look for the stunning `Souvenir d'Andr Chaudron'.

A bit later, for a small bed, an easy mix is all the eryngiums you can find (Eryngium alpinum, E planum and the silvery green, wildly ruffed, biennial E giganteum are all essential), and day lilies, whether stylish lemons such as `Hyperion' and `Whichford', or dusty pinks (or both). Back with anthemis `Sunrise' and white aconitums.

Best of all, plan for later still; you're probably off for parts of high summer, so won't be near the garden. Plan for warm and quiet afternoons at the end of the season: September, October, even November. That means plenty of penstemons and asters, whichever of the Japanese anemones you can find, plus rudbeckias, heleniums, agastaches, even some of the better dahlias. That's virtually an instant planting.

Penstemons are easy from seed, though choicer varieties are now being micropropagated, and fine plants such as `Hidcote Pink', `Sour Grapes', `Garnet', and so on, are easy to come by. Asters: use the enchanting species, for all are reasonably self-supporting, and have much more finesse than many of the Michaelmas daisies. Especially good are forms of Aster laterifolius and A ericoides.

In autumn, the colours pretty much look after themselves; endless shades of pink, violet, blue, bronze, and sharp or apricot yellows from the last of the crocosmias, the whole lot unified by the fading light.

There. Time to think of some interesting things for next season such as eremuruses and cimicifugas.

And the downside? Borders do need a bit of work. Luxuriance is the thing, so feed and water well. Compost and manure are best for the first, a well or a wet climate best for the second. Staking needn't be a headache, unless you like your plants regimented, in which case you'll get a migraine. Keep the staking to a minimum by using wiry-stemmed varieties, or by not minding the flop. Support systems, whether of wire or pigeon netting, always show. There's not much you can do about delphiniums. Stake them, but everything else leave alone, unless you live in a wind-tunnel.

A new border will make a real show by the second season. You'll have a couple of peak years, then everything will get choked. Lift in earliest spring, divide, discard at least half, then replant. But the herbaceous flora is so immensely rich that you have a perfect opportunity to try totally different plants.

Oddly, American friends are unaware of an irony: three quarters of the "English" border comes from America. Modern lupins and delphiniums all derive from American species. Penstemons are all American, as are rudbeckias, heleniums, almost all the border's asters, gaillardias, agastaches, coreopsis, marvellous echinaceas, monardas, liatris, cimicifugas, oenotheras, most lysimachias and on and on .... Americans, where would we be without them?