The Herculean effort was aided by several local volunteers and two friends who came for two days from Taranaki and Matamata.
Mrs Greener said the grotto featured 11 displays, each themed in one way or another.
New for this year was a "funky" tree based on the Grinch that Stole Christmas, by Dr Suess.
The Frozen room would appeal to "little princesses" while the Tui tree would appeal to the guys, she said.
Other attractions include a woodland display, a red room, a childrens area, a gingerbread room, a white and crystal room and a common room where children can put decorations on trees.
The grotto is at 304 Broadway and is open Monday to Thursday evenings from 7.30pm to 9.30pm and Friday to Sunday between 1pm and 4.30pm.
"In the final week last year we had people queuing up for over an hour."
Entry is $3 for adults and $2 for children under 14.
Mrs Greener said she wanted to thank local businesses and people for helping out with the costs and running the grotto with small donations.