They should be planted nearer to the surface than most lilies, with only 1in (2.5cm) of soil above the "nose". Plant them away from other lilies in the garden because they carry a virus, which is symptomless for them but not for other species and varieties. I would not be without this lily because for me it represents the traditional cottage garden. Pick plums as soon as they ripen. You may have to go over the tree several times, as they ripen over a period. Distract the wasps with a jamjar, half-filled with sugar solution, hanging from a branch.
Pinch out or "stop" the growing tips of tomato plants, so that their energy can go into growing and ripening the remaining tomatoes before the nights really start to draw in. On the subject of long nights - they are beginning to get colder - make sure the greenhouse vents are closed before bedtime.
Also, dig up onions and shallots whose tops have died down. Leave them somewhere airy under cover to dry and then store for the winter. Any "bull- necked" ones should be eaten at once, for they will not store well.
In the garden of the Somerset cottage I've just bought is a strange border planted with varying shades of (unfortunately, clashing) red flowers and leaves that stands at odds with the blowzy, romantic and unstructured style of the rest of the space. It seems a peculiar piece of planting, but I know who to blame for it.
Over the hill, at Hadspen Garden, Sandra and Nori Pope have created a stunning garden of "developing monochromes" - where blocks of toning hues merge in a spectrum of colour, from yellow to scarlet to plum to crimson and pastels against a curved brick wall - with such confidence that it is tempting to adopt their style without possessing either their eye or their vast knowledge of plants. Like the thousands of "white gardens" engendered by Vita Sackville-West's original at Sissinghurst, in the coming years, when you spot clumps of nearly correspondent colours next door to each other, you can be sure there will be a copy of the Popes' new Colour by Design in the house, probably alongside that other modern style bible, the River Cafe Cookbook.
But perhaps the subtitle of the book should be Don't Try This at Home. When Nori suggests I meet him at 6.30am, I am not entirely sure whether he is joking. With his wife Sandra away in Ottawa, he is up early, tidying the borders to be ready for Hadspen's opening to the public later that day. "This is not an easy maintenance garden," he says. "We deadhead every day and we don't have weeds because they don't get a chance to seed."
It doesn't mean it has an overmanicured look to it - quite the opposite. One of its charms is its wild exuberance, but the plants have to be on their best form or they are cut back, hidden or moved.
Rather than working from the outside in - choosing a plant because it has caught your eye, then deciding where to put it - the Popes see their garden as a whole picture and choose (or even breed) the appropriate plant to fit a particular space.
Even the potager is part of the picture. Their attitude towards the garden is ruthless: "Our image of it is complete," says Nori. "When things are outside that image we consider them; if they are in the wrong line or tone or hue, then they have to go. This garden is about what it looks like as a whole."
Although Nori likes gardening for its "peasantry" appeal, he and Sandra are hardly horny-handed sons of toil. "Gardening is so physical and yet artistic," he says, "like being a dancer". Their book is filled with allusions to art, philosophy, science, religion - even Dr Seuss.
The predominant metaphor they use, however, is that of music, although neither of them is a musician - "I play the piano very badly," says Nori. "It's a good thing I'm a gardener." Words such as "notes", "composition" and "melody" abound and, in the introduction to the book, while explaining how they can work together without tearing each other's hair out, they write: "People often ask us, in an amazed way, `How do you possibly garden together?' - yet they never stop to question a couple playing a duet."
While Sandra is the maestro behind the spectrum border, Nori provides the plants that sing her tune. All this intellectualisation makes the Popes sound rather po-faced but they mix a certain North American earnestness with lightheartedness, and I nearly fell over backwards when Nori said Sandra was away visiting her grandchildren. Fresh air keeps you young; it must be nice to have grandparents who can write as a caption to a beautiful photograph by Clive Nichols: "the leviathan Gunnera manicata begins to unfurl its giant green body far too early in the year. Like a maladjusted pet, it is wonderful in its cranky behaviour and grand thorny leaves: it cannot bear to hibernate long enough, yet is a martyr to frost."
The Popes first encountered Hadspen in 1986 when they were on sabbatical from their native Canada. Other parts of the grounds had once been gardened by Penelope Hobhouse, but the walled area was a derelict kitchen garden. "People left their 50p by the door and went round it, if they weren't bitten by the dogs first," says Nori. "We saw it in the late autumn; it looked amazing."
They struck a deal with the owner, set up a nursery immediately, cleared the weeds and got stuck into the task of creating the abundance that is there today.
"We began with the colour of the brick wall and planted in relationship to it. If you start with a theme or a melody, you develop it and work it through. We said we would leave when the garden is finished. That's pretty safe."
`Colour by Design' is published on 27 August (Conran Octopus, pounds 25)Reuse content