As I write, spring in reality has been evident in The Hills now for weeks - from about the first week in August, in fact.

Azaleas and ornamental fruit trees are in full bloom and many local streets are a riot of colour.

My too-many bonsais, which had a brief period of

dormancy during winter, are well into bud or in actual flower, catching me and the pruning shears by surprise.

At Ray Nechi's bonsai nursery in Kenthurst a few weeks ago, while discussing the changing weather pattern, he joked to get-back, hands-away gesticulation: ''Whoa, spring, whoa!'''

When spring begins officially on September 1, we'll have put behind us the coldest August in 13 years.

But previous warm spells in a relatively mild winter tricked the weather gods. Or did they?

In The Sydney Morning Herald last week, Tim Entwisle, the executive director of the Botanic Gardens Trusts, reckoned it was time to redraw our seasons, starting spring on August 1, four weeks early.

''Every year we think spring has come earlier,'' he said. ''But really spring in Sydney actually starts in late July and August for many natives and garden plants. We'd be better to think of spring as being four months, from August to November.''

Spring Down Under was defined simply by colonial tradition - the NSW Corps changed uniforms at the first of the month.

September 1 through November 30 also corresponds to the fall months of the northern hemisphere.

Entwisle believes it's one tradition we ought to

hose down.

By having four ''artificial' seasons, people lose touch with the realities of the environment and nature's subtle changes. If we had real seasons, not unrealistic ones, we would all be more aware of changes in the environment, especially climate change.

If Entwisle had his way, we'd probably compost autumn and just live with three proper seasons winter, spring, summer.

For most serious gardeners, though, spring is just

another title. For green thumbs, the annual gardening cycle is really determined by what is actually happening in the orchards and vegie patches and flower beds around the nation.

Once the sap rises and the buds form, spring has

sprung on Oz, regardless of the date.