Sydney's Christmas celebrations kick off

Aine Fox

Sydney's countdown to December 25 is officially on after the tallest Christmas tree in NSW - covered in beach ball baubles and native flowers - was unveiled.

Lord Mayor Clover Moore described this year's 25-metre decorative centrepiece in Martin Place as sustainable and environmentally friendly -with its LED lights - as well as "Australian and fun".

The lord mayor launched the city's 30-day $3 million program of Christmas events on Thursday, at the end of what she described as a "very challenging year" when high street retailers struggled and parts of the state were devastated by drought and bushfire.

"People need support at this special time and we're going to provide it here in the city and you are all very welcome," Ms Moore told a small crowd gathered by the tree.

Events in the run-up to December 25 include Christmas concerts, festive lights along the city's streets and family-friendly activities.

This year's charity partner is Surf Life Saving NSW and collections will also be held for drought and bushfire appeals.