I usually see Stonehenge when I'm storming home down the A303 with Eric Clapton pounding in my ears and a half-eaten Mars Bar in my hand. It seems disrespectful to flash by it like this. Suddenly, there they are, the stones, and equally suddenly gone. They don't have a chance to speak of their consequence, their gravity, their implications.
You should have to walk a considerable distance to find Stonehenge, to take it in as it slowly rises, naked, from the plain, to watch the rectangles of sky between the monoliths change as you approach. If it is pouring with rain, so much the better. No effort we make to visit this place can rival the effort made by its builders. We demean that by glancing at it idly as we pass by at 60mph.
Travelling at the speed we do, it is difficult for us to capture now those 'peculiar emotions' that the young Joseph Hooker described on seeing new countries for the first time. During his lifetime (1817-1911), there were still opportunities for real discovery.
Hooker, who went on to become an influential Director of the Royal Botanic Gardens at Kew, made his first expedition when he was only 22. Sailing on the Erebus, he left England on 30 September 1839 as official naturalist on a voyage to determine the exact position of the South Magnetic Pole. The Admiralty supplied him with two tin boxes for collecting plants, 25 reams of blotting paper to dry and press them, and two Wardian cases, like miniature greenhouses, in which to bring live plants back to Kew. Everything else, he had to provide himself.
On New Year's Day 1841, over 15 months after its departure from England, the Erebus finally crossed into the Antarctic Circle. In his journal, Hooker described the overwhelming vista of 'snowy precipices covered with an immense bank of broken clouds, each tinged of a golden colour by the never-setting sun; above these rose the immensely high peaks of land, towering up against a beautifully blue clear sky, above which was another canopy of dark, lowering clouds, their lower edges of a bright golden red colour. It was one of the most gorgeous sights I ever witnessed.'
Hooker's best-known expedition took him to India, where, close to the great mountain, Kangchenjunga, he found vast bushes of Rhododendron falconeri, growing at 10,000ft with leaves 19 inches long. In Bhutan, he collected sweet-smelling R. griffithianum, like a 'fine lily', each pale flower in a truss measuring as much as seven inches across.
Painstakingly collecting seeds of these beauties, Hooker packed them in tins and dispatched them to his father at Kew. Given the long, arduous process by which these new plants were introduced into cultivation, did gardeners then value them more? I think they did. The garden centre, the micro-propagation unit, has reduced plants to commodities, to so many tins of baked beans ranged on the shelf. It has, of course, also made them cheaper.
It is only now, too, that through TV makeover programmes, we have been introduced to the concept of gardening against the clock. Surely, though, most of us garden to escape the clock. At the very heart of the business is the feeling that, when we garden, we abandon a timetable constructed around dentist's appointments, car services and the possible arrival of trains, to plunge headlong into a completely different timetable, an immense and inexorable one entirely outside our control, defined by weather, and above all the seasons.
The Slow Food movement has had some success in increasing respect for the ingredients with which we cook: good beef, properly reared and hung, decent tomatoes allowed to develop flavour and ripen without the aid of a man in a white coat. So I'm nominating 2007 as the year for Slow Gardening. Chill out. Relax. Observe. Take time to admire the way a seedling pushes through the earth, its back humped into a croquet hoop with the effort. Even if it is a seedling of a weed like groundsel, it's still a miracle of tenacity and endurance. Grow something from seed yourself. If it's something useful - basil, coriander, rocket - so much the better. Plant a tree. Train a clematis.
The point of gardening is the doing of it, not having got it done. It's the process that matters, though it is of course directed towards an end result. It's rare now for people to stay in the same place for generation after generation. But continuity produces a tangible effect in a garden: hedges bulge, trees cast ever-longer shadows over a lawn, wisterias send out tendrils to close up the windows.
But we live in an impatient age, used to quick results. Because people move around more than they used to, they don't plant things that won't immediately benefit them. There is a danger in this. It leads to layouts that, like instant food, are ultimately unsatisfying. The ingredients are limited and, after the initial gratification, there is no lingering sense of pleasure. But a holly tree, though slow, can give you that in spades.
In your garden, you can make a stand against the prevailing trashy mood of the time. The great 18th-century landscape gardens were made at a time when their busy agricultural owners were fencing and hedging and enclosing land. Capability Brown's idealised landscapes reminded them of a pastoral, dreamy past, before turnips, before corn.
If the mood now is instant, disposable, then our gardens can become places where the opposite things are going on. We should be planting slow, steady, sustaining things. In the garden at least, if in no other part of our lives, we can dream a future.
A satisfying garden is a resonant one - a garden that has things going on in it that are not of the here and now. Built into it there may be messages from previous owners of the garden and previous uses of the land.
Huge pear trees in suburban gardens round the outskirts of London remind us of the orchards that used to feed the tenement dwellers of the city. Big old bay trees planted close to houses recall the time when gardeners believed, quite literally, that 'neither witch nor devil, thunder nor lightning will hurt a man in the place where a bay tree is' (as the 17th-century herbalist Nicholas Culpeper put it).
A holly at the bottom of the garden may be the last remnant of the natural landscape that existed before urbanisation spread over your patch. That is quite a comforting thought - a thread that connects the before with the after. It need not stop you gardening round it, planting cyclamen close to its trunk and ferns to unfold after the holly's berries have gone. Tune yourself into the holly's pace of life.