Gardening: A mutiny on the gypsophila border: Anna Pavord finds her garden-cred in question after a planting disaster in a sun-drenched, south-facing dream bed

A little while back I wrote a confident piece, entitled 'The Grand Border Wrecking', about a south-facing strip of ground in front of my house. I had emptied it and replanted it as a ribbon border using (among other plants) rows of iris, gypsophila, penstemon and violas. It was a disaster. At this stage I should perhaps tender my resignation and stump off into the gloom of a November night to commit hara-kiri in the potting shed.

That now painful article explained the border's history as an early dumping ground when we first arrived here, a fate from which it never recovered. It is one of a pair of borders that stretch for about 20ft under the windows of the house and that are about 4ft wide.

The disaster was caused principally by the gypsophilas. They died in droves. I tried spring planting, summer planting and autumn planting. I dug in grit, sand and bonemeal. I lost more gypsophilas than any self-respecting gardening correspondent should ever admit to. And I did what I would always advise other gardeners not to do: I went on planting the wretched things long after it should have been evident that a gypsophila was as likely to live in this border as if it was planted on the central reservation of the M1.

I had a few qualms about including gypsophila in the first place, given my generally damp, heavy soil, but this border was drier and better drained than most of the garden. I thought I could get away with it, and nothing else I could think of would produce quite the effect I wanted: billows of tiny white flowers resting against the strong upright sword foliage of Iris ochroleuca behind.

The irises are fine. That bit at least works well, a regiment of iris with 4ft leaves and white fleur-de-lis flowers drawn up along the back of the border against the house wall. The front line has also done its bit - 'Prince Henry' violas which have flowered themselves silly all year since spring.

The only tricky thing with violas is steeling yourself to shear them down in late summer. It seems sacrilegious to cut them down while they are still in full flow, but it forces the plant to make a strong new rosette of foliage, which will see it through the winter.

At the start of summer, having lost a third lot of gypsophilas and yanked out the penstemons, which made too much leaf and too little flower, I tried a temporary planting of annual cleomes and asters with mounds of scented-leaved geraniums behind the violas. They alternated with clumps of silver, cabbagey echeverias.

It was not the right kind of summer for this sort of planting. That is my excuse, anyway. The cleome is a showy plant, stout-stemmed, growing to about 4ft high with big rounded heads of flower in white and various shades of pink. The stamens stick out way beyond the petals, like the legs of drunken spiders. The foliage is hand-shaped and handsome.

I sowed the seed towards the end of March and, not being hardy, the cleomes were set out in May along with the asters. By August, they showed great promise. There were bunches of buds on top of all the tall, well-grown stems. Three months later, they are still showing great promise. Absolutely nothing has happened in the meantime. When frost hits them of course, they will die, as the asters did some time ago, melting in September's rain.

The cleomes' behaviour is odder. I noticed in an old gardening book (1886), though, that it was classed as a 'stove annual', suitable only for growing under glass. Those gardeners were perhaps more realistic in assessing its potential. This cleome's home is in the tropics. It needs plenty of heat.

Cleomes have been flowering in other gardens this year, though, so the weather is not entirely to blame. Talking to the head gardener in charge of one of these displays, I learnt the secret. His plants are already almost fully grown when he sets them out. He pots the seedlings on several times so that they never check. By the time they finally see fresh air, they are in 6in pots and feel they have already had a summer's growing season. That is a difficult trick to bring off without a greenhouse.

For the moment, the bed is packed full of grey-leaved Brompton stocks and deep- purple tulips, a single late variety called 'Queen of Night'. I am hoping that not too many of the stocks will be purple, otherwise the effect will be more funereal than I intended. This gives me a breathing space to work out another more permanent planting scheme, which keeps the iris at the back, the violas, the mounds of scented-leaved geraniums and the chubby echeverias at the front, and finds some new solution for the ground in between.

The geraniums, a mixture of Pelargonium quercifolium with stiff oak-shaped leaves, and 'Chocolate Peppermint' with soft, hairy, rounded leaves, are not much interested in flowering. Nor of course are the echeverias. Whatever happens behind them needs to be flowery.

The simple answer would be to fill the space behind with argyranthemums, the non-stop pale-yellow 'Jamaica Primrose' perhaps, or the needle-leaved white-flowered 'Chelsea Girl'. But I am already lifting the geraniums and the echeverias to overwinter them under cover. The argyranthemums would need the same treatment, which would leave the bed looking rather naked in winter.

Perhaps this does not matter. There is a winter bed around the corner under yew trees, with cyclamen, now in superb marbled leaf, epimediums, Lenten hellebores, snowdrops and Helleborus argutifolius. This bed, in an unpropitious, dark, gloomy situation has never been a problem. The other, which has all the advantages of sun, shelter and an open, southern aspect, continues to niggle.

Partly this is to do with temperament. I am happier in shade than in sun. I am more in tune with quiet, leafy, shade plants than noisy sun ones. But this sunny border is what garden writers call an 'opportunity'. It needs to contrast with the damp leafiness of the rest of the garden.

Poppies are my other thought. They would be no more permanent than the argyranthemums so the winter problem remains. But I would like to grow them and there is nowhere else they would be so well suited.

The ones I have in mind are the tissue- paper ones called 'Mother of Pearl' or 'Fairy Wings' or 'Constance Finnis'. They are annuals but, unlike the brilliant red field poppies, they flower in dusty blue and grey and peach and white, the petals stained and speckled with darker colour.

My only worry is that they will be too ethereal for the chunky geraniums. But I had perhaps better shut up about this border. Another disaster would do my garden-cred no good at all.