The giant redwood, which is the tallest living Christmas tree in England is 36 metres tall.
It has come to Wakehurst in Ardingly for the 25th year running.
Aborists and horticultural staff used elevated moving platforms, carefully passing the lights to professional tree climbers suspended throughout the tree branches to create the magical masterpiece.
Iain Parkinson, Conservation and Arboretum manager, said: “The giant redwood is one of Wakehurst’s best-loved storm survivors and it is clearly very happy where it is planted.
“We lost 20,000 trees in the Great Storm of 1987. This tree has a flexible trunk meaning it swayed in the high wind but wasn’t uprooted.
“It has certainly done us proud and people come from far and wide to see it lit with all the lights – it is a really magical sight.”
The decorating of the Christmas tree marks the start of preparations for Wakehurst’s winter lantern festival – Glow Wild, which sees the botanic gardens, woodland and house brought to life with white paper lanterns during December.
The popular winter festival has already sold all of its 38,000 available tickets.
The festival runs on Thursdays, Fridays, Saturdays and Sundays from November 30, until December 17.
The giant redwood was planted at Wakehurst in the late 1890s and was one of the first exotic trees to be put in place on estate, which spans more than 500 acres.
Pilots are said to use the Christmas tree as a beacon when landing their planes at nearby Gatwick airport.
To find out more about Wakehurst visit www.kew.org/visit-wakehurst.