Whenever there's a new nought in the year, retrospection takes over: the best of the decade, the worst of the decade – B-listers rush to tell us what they remember of the past 10 years. I remember very little, but that's because gardeners are hard-wired to look forward, not back. My impression is that we've been force-fed with grasses and green roofs, that grow-your-own has a new gloss on it and that there has been a lot of rain. Shrubs have got less and less attention while hellebores, dahlias, alliums and snowdrops have reinvented themselves in surprising and lucrative ways. Who would ever have thought that a single snowdrop bulb would sell for £100?
At the beginning of what's now being called the Noughties, my hope was that gardeners would throw away the rule books and learn again to use their eyes, trust their instincts. But it hasn't happened like that. Websites and blogs have multiplied, fertilised by a curious anxiety about the natural world. But that world is not going to get more familiar by way of a computer screen. "I looked it up on Google" became the refrain of the decade and shows no sign of fading. Being outside is what matters in gardening, where, given time, you can begin to absorb the complex set of circumstances that makes plants grow. Or not. The "not" is much more likely to be our fault than theirs. You can hardly blame a blue Atlantic cedar for dropping its needles if it's been stuffed into an aluminium tub far too small to sustain it.
Respect is what plants need. Even though, in the past 10 years, more words have been written about "respect for the environment" than you could read in a whole lifetime, the effect has been not to draw us into this thing, but to separate us from it. If you really respect other living things, you acknowledge their right to lives as full and happy as you hope yours is going to be. If you stuff a cedar into a pot, to fulfil some transitory notion of style, then you deny the cedar the possibility of ever fulfilling what it set out to do. Its destiny is to grow into a fabulous monster at least 50ft tall.
In terms of style, the Chelsea Flower Show offers a certain kind of window onto what was thought good at the time. In May 2000, the prestigious Best in Show award went to the Gardens Illustrated garden, designed by Piet Oudolf and Arne Maynard. I first wrote about Oudolf in 1997, when he laid out a garden for John Coke at Green Farm Plants in Hampshire, but his name was still unfamiliar when he planted up his amazing Chelsea garden with its billowing box hedges. The borders had the texture of faded tapestries, with claret-coloured astrantia, knautia, dark-leaved cimicifuga and the purplish-blue salvia 'Mainacht'.
There's another thing that's happened over the past 10 years: more plants with German names. We have 'Goldschlier' and 'Tautrager', 'Kupfersprudel' and 'Rubinkuppel'. The names came in with the plants of the New Perennial Movement, thought to be a very Noughties thing (but actually much more like the Old Perennial Movement than any of its protagonists wanted to believe). For good reasons – colder winters, less rich soil – grasses had traditionally been used more by German garden designers than British ones. German nurserymen bred and selected some excellent kinds which naturally kept their names when they first started to be sold in the UK.
In 2001, the Chelsea money was on Tom Stuart-Smith, the impossibly charming, impossibly good-looking designer who, over the past 10 years, has won seven gold medals at Chelsea and three Best in Shows. But despite his amazing lime trees and a very "then" planting with plenty of miscanthus, the top award went to Professor Fukuhara and his Japanese tea garden. What I mostly remember about that garden was a notice stuck in the raked sand in front of the tea house on press day. "Keep off or die" it said. I believed it.
Gardens in the Japanese style work well at shows like Chelsea because they are meant to be static set pieces, the plants living sculptures. A fabulous piece of cloud topiary in a Japanese garden sponsored by Honda in 2002 was probably the most expensive plant ever used in a show garden at Chelsea. Before the show had even opened, it was sold to the chairman of the security firm Group 4. It should be safe with him.
It was an interesting year, 2002 – perhaps the first time that a really good Back to Nature garden (an obsession during this past decade) appeared on the Chelsea radar. It came from a young Irish designer, Mary Reynolds, who had very little money to spend on it. I first met her salvaging plants from other people's skips and she put those finds to brilliant use in a garden surrounded by a wall of round granite boulders. Small creeping ferns, cinquefoil, herb Robert and other wild plants crept from the gaps between the stones. In the front corner stood an old thorn tree, just breaking into bloom. The planting around the central pond was very quiet, grass studded with daisies and hawkweed. It was superbly done. Believable. And in all senses, very green.
Diarmuid Gavin – remember him? – was back at Chelsea in 2005, undeterred by the rubbishing his garden had got the previous year. It was funded by the Lottery – why? Now there's a good thing that has happened over the past decade. We no longer have the Diarmuid (or the Llewellyn-Bowen) leering out from our televisions. I'm still waiting for some really good gardening programmes, though. Programme-makers are terrified of seeming elitist. They are being extraordinarily patronising in supposing that we can't dwell on any subject for more than two minutes at a time. There are 26 million of us gardeners in the UK. Do the programme-makers ever wonder why so few of us are watching what they give us?
The garden as anchor and refuge is what I see for the decade to come. The garden as teacher, as a place of calm. Of grace. Of happiness. Of all that is good. My advice? Stop Googling. Start weeding.