Country & Garden: A season of fruitful mellowness

We had globe artichokes for supper this week, glistening with butter. Afterwards, we had raspberries. Both were picked fresh from the garden.

What on earth is going on out there? The artichokes are pushing up fountains of fresh foliage at a time when I would normally be advising myself to cover up the crowns against frost. This is reckless behaviour, I tell them sternly. Why not, they reply and they are right. It is only we pathetic humans who need rules to prop us up. Plants are opportunists and if a mild autumn is handed to them, they will make the best of it. They don't know when such luck will come their way again.

Instead of taking that laid-back approach, gardeners fret when plants change the agenda. Nasturtiums are still romping among the dahlias. That at least is a combination I planned. But pale yellow primroses are coming out under a `Buff Beauty' rose, still laden with its apricot-coloured flowers. The two together look hideous. But will that combination happen again? The rose should have packed up ages ago and be waiting, meekly, to be pruned. The primroses are supposed to be a spring act, not an autumn one.

"Oh, primroses!" exclaimed Nigel Hepper, a Kew herbarium botanist. "I gave them up in despair." Not for aesthetic reasons, that is, but because their flowering times are more than usually erratic.

Mr Hepper has spent most of his working life as a taxonomist at Kew, but he has also pioneered the fascinating science of phenology - the study of the timing of recurring natural phenomena, especially in relation to the climate.

For years he has kept records of the first flowering times of several thousand plants at Kew and in his own garden, noting some extraordinary variations. But primroses were just too variable to be useful. The steadiest plants are apple trees and, surprisingly, narcissus, which refuse to budge from their allotted slots, whatever weather condition is thrown at them.

Day length is an important arbiter of growth for some plants, such as garlic, and Mr Hepper points out that the plants that respond to this factor more strongly than they do to weather conditions, will always be more reliable in their behaviour.

Weather is an obsession in this country and seems always to have been so. For centuries, long before the Met Office set itself up as the oracle, people have been measuring and recording weather, trying to pattern events, to make theories and predict the future. Temperature has been officially recorded since 1659, rainfall since 1766, hours of sunshine since 1909.

For weather freaks, this is yet another freakish year, for 10 out of the last 11 months have been warmer than average. The assessments of temperature, rainfall and sunshine produced by the climate department at the London Weather Centre show that last winter, on 6 January, London had the month's warmest day ever recorded (16C). Generally it was the sunniest winter for 10 years. Although there was 8cms of snow at Bristol Airport on 14 April, the spring too was generally mild, the warmest since 1992.

The Met Office called the summer "statistically uneventful" but on average, we got 6.75 hours of sunshine a day, rather better than the average for the last 30 years. Last year, we got only a measly 5.53 hours. This autumn has been the sunniest for 40 years and the second sunniest since sunshine records began, 90 years ago. At this time of the year, sunny doesn't necessarily mean warm, but it has been that too, with a mean temperature of 11.2C.

In the garden, salvias, fuchsias, geraniums have been carrying on as if winter was a thing of the past. Is it? We only think so because we don't have very long memories, says Nathan Powell of the Met Office. "Exceptionally mild autumns have certainly been a feature of the last five years," he points out, "but for the three years between 1990 and 1993, we had horrible autumns, really cold and miserable."

Mild autumns such as this have caused some weird collisions in the garden. The yellow coreopsis `Early Sunrise' (an annual) refuses to believe that summer is over and is flowering more vigorously now than it ever did in August or September.

Autumn troops, such as cyclamen and nerines, are determined to keep going too. Winter jasmine is in full flow. Ceanothus `Trewithen Blue' thinks it is already next April and is also blooming merrily.

Anything that shortens the dead period of winter is a good thing, as far as I am concerned, but the present explosion (a friend counted 30 different flowers out in her garden this week) creates practical problems. I've still got mounds of tulips to plant because the pots I want to put them in are still full of osteospermums and argyranthemums, looking wonderful. I took cuttings at the end of September, but it would be sacrilege to throw the plants themselves away. They have finally worked themselves up to a frenzy of flowering. I've repotted geraniums and fuchsias to release tubs for tulips, but the argyranthemums and osteospermums are too big and unwieldy to move.

Argyranthemums, with their daisy flowers, are by nature sub-shrubs, not annuals, so it isn't odd that they should go on growing, given the chance. In their natural habitats in Madeira and the Canary Islands, they would be doing that anyway, for mild winters are the norm there. A yellow flowered argyranthemum `Jamaica Primrose' in a cottage garden near our house still has hundreds of flowers on a bush fully three feet across.

I grew a new variety of `Summer Stars' this year, pink daisies on top of very finely cut grey foliage. It is in a big pot with two plants of an excellent new osteospermum called `Nasinga Purple'.

Osteospermums are sub-shrubs too, natives of southern Africa, and like the argyranthemums, are merely reverting to type, rather than re-inventing themselves.

If a weatherman misinterprets the signals, the worst he can expect is a rude headline in The Sun. For a plant, there is more at stake. If it wrongly construes the signals it is getting from the weather, it dies.

Ever since plants arrived on the scene, they have been able to monitor their environments with machinery much more finely tuned than anything even the Met Office can devise. So why aren't there phenologists all over the place, noting flowering times? Plants might be trying to tell us something we need to know.

Ensuring continuity is one of the problems, as Nigel Hepper points out. You need to have a long, unbroken set of records, longer than one man's lifetime, if you want to deduce trends. The hard labour of gathering raw data makes phenology an unfashionable occupation. Some of Mr Hepper's records were brought to an abrupt end by the great storms of 1987 and 1990. In the 1987 gale, the wind which hurtled at 70 knots through the garden brought down 150 evergreens.

Like most other scientists I know, Mr Hepper will not be pinned down on the million-dollar question. Are we responsible for global warming (the overall temperature has risen by 0.5C since 1900 and scientists predict that global warming will cause the seas to rise by 70 metres)? Or is this a temporary blip in a much bigger and as yet unrevealed story?

For an answer, forget the scientists. Go and ask your sunflowers.