It was nice weather for duckweed

Chelsea offered executive gardens, a blooming kitchen garden and a writer's garden, much envied by Anna Pavord

Designer duckweed was one of the major keynotes of the Chelsea Flower Show this year. It lay in a lazy veil over the pool in Diarmuid Gavin's relaxed Irish Garden. It lapped gently against the sides of the moat surrounding the tree house in Bunny Guinness's Writer's Garden. A few brave little rafts of it bobbed choppily about under the Brussels sprout fountain in Country Living's decorative Kitchen Garden.

Consequently, I have torn up all the notes I made a little while ago on ways of getting rid of the stuff: barley straw, natural algicides, water fleas. I am horribly behind the times. Mr Gavin carried his duckweed in a jam-jar all the way from Dublin. I wonder if anybody bought it yesterday when the show was dismantled?

The fabulous piece of cloud topiary in the Honda Tea Garden was sold even before the show opened. It was made from a Japanese holly, Ilex crenata, about 4ft high with a trunk as thick as my arm. The leaves were as small as box and the bark a smooth soft grey. Short branches came out almost horizontally from the main trunk and the foliage on them was clipped into soft rounded pillows of green.

Of all the things in the show, this is what I coveted most. Julian Dowle, who has joined company with the Japanese architect Koji Ninomiya to build Japanese gardens in this country, said he found it in a Belgian nursery which had imported it from northern Japan. By now it will be on its way to Broadway in the Cotswolds to embellish the garden of the chairman of Group 4. It should be safe with him.

The Tea Garden, which was beautifully constructed, won a gold medal at Chelsea. Japanese gardens are popular with company chairmen, said Mr Dowle. They like the storyline that goes with them, the bits about harbour stones and demons only travelling in straight lines. Having mastered the brief, they can then march guests round the garden with confidence. There are only two plant names to learn: bamboo and maple.

Country Living is equally clear about its potential market and its gold medal garden, designed by Rupert Golby, was a triumph. Building the crumble factor into a Chelsea garden is a ticklish business - a chip off a brick here, a plant tumbling out of a crack there - and Mr Golby's eye never let him down. Even the "self-seeded" aquilegias bobbing up between the rows of cabbages in this kitchen garden looked settled for the season. I wonder where theyhave ended up?

The big plot was divided into four by wide paths, paved with a carefully random mixture of brick and quarry tiles. In the centre at the crossing of the paths was a circular pool with the Brussels sprout fountain, made by sculptor Simon Allison. One path led into the garden through a tunnel of hazel sticks, supporting 'Painted Lady' runner beans. That is an idea I am going to copy next year.

The sticks, about 8ft long, were pushed into the ground 18 inches apart, on either side of the brick path. Then they were joined by a third length of hazel bowed over the top of the path and lashed to the supports either side. When all these big hoops were in place, long lengths of hazel were tied horizontally along the tunnel, joining each hoop to its neighbour and making a lattice framework ideal for the beans.

The garden, said Mr Golby, is "emphatically not a potager. It's a productive, working kitchen garden that also happens to look attractive". Sumptuous, I thought.

Tall purple drumstick alliums poked their heads out of rows of purple beet and cabbage. Blue aquilegias dangled over the fleshy leaves of 'Red Drumhead' cabbage. The leaves of carrot, onion and curly kale made ribbons of contrasting foliage across one of the plots, with clumps of tall cornflowers at the corners.

Flowers were well used here. This was not a flower garden with a few token vegetables pushed in for novelty's sake. It was, as Mr Golby intended, a proper vegetable plot with flowers squeezing in where they could. Bright orange Californian poppies jostled in the onion bed, brilliant blue anchusa overhung mounds of the purple-leaved sage and marigolds toppled over the path with fluffy plumes of fennel behind them.

"It may look a dream to you," said Colin Randel of Suttons Seeds, "but it was a nightmare for me." He was responsible for raising all the vegetables and annual flowers for the garden and brought three lorry loads of plants to Chelsea, planted in 1,800 containers.

Carrots growing in long troughs, runner beans in huge pots, were so cunningly sunk into the ground you never saw the joins. But Mr Randel said it could scarcely have been a more difficult growing season with temperatures leaping about as wildly as a frog on the bottle.

Many people, not just scribblers, looked enviously at the tree house which was the centrepiece of the Writer's Garden, Bunny Guinness's design for Wyevale Garden Centres.

The beech tree supporting the small Gothic tree house was picked out at the end of last year, lifted, root-trimmed and kept in a monster net of sacking until its expedition to Chelsea. Some of its branches poked out through the roof of the tree house.

Wide, generous wooden steps lined with pots of geranium, thrift and pansies led up to the tree house and there was a separate escape route at the back by way of a bridge over the circular moat.

I was very envious of that. By the time I hear visitors approaching down the passage, I am doomed as far as escape goes. There is only one way out of the study and that leads straight into the arms of any arrivals.

The planting in the shade under the tree house was particularly successful: hostas and ferns snuffling round together and demonstrating that 40 shades of green can be every bit as successful as planting with a more varied palette.

The only false note in this garden was struck by the grass in front of the tree house. It was uncut, which was as it should be, but the turf was suspiciously weed free. Was the writer sneaking down from his bolt hole and dosing it in between paragraphs?

Outside our front door is a sea of daisies, plantains, speedwell and creeping buttercup which I am willing to sell at an appropriately high price to any garden designer looking for a genuine hack's lawn for next year's Chelsea. Then I can spend the money on a splendid griffin which was spreading its wings in a menacing way over the box hedges of Crowther's garden. It had come from Skeffington Hall in Lincolnshire and was dated 1844.

The Honda Tea Garden was designed and built by the Julian Dowle Partnership, The Old Malt House, High Street, Newent, Gloucestershire GL18 1AY (01531 820512); Country Living's garden, designed by Rupert Golby, was built by SHAW Landscapes, Kielder Avenue, Beacon Lane, Cramlington, Northumberland NE23 8JT (01670 730643). SHAW is a charity providing support for people with learning or physical disabilities. The bronze Brussels sprout fountain was made by Simon Allison, Lock Bund, Fishermans Cottage, Appletree Lane, Cropredy, Banbury, Oxfordshire OX17 1PZ (01295 758066). The Writer's Garden was designed by Bunny Guinness and the Wyevale Design Team, King's Acre Road, Hereford HR4 0SE (01432 276568). Crowther's is at Syon Lodge, Busch Corner, London Road, Isleworth, Middlesex TW7 5BH (0181-560 7978).