Thrifty beer drinkers vandalised the St Kilda Botanical Gardens overnight smashing windows and building an installation with their empty tinnies.
A Victorian Police spokeswoman said it was estimated that the vandals caused $10,000 in damage.
Police arrested 12 people when they were called to a disturbance in the gardens after 10pm.
The revellers were both men and women, aged 19 to 25 years and from the suburbs of Yallambie, Elwood, Caulfield North, Caulfield South, Brighton, Port Melbourne, Brunswick, St Kilda, Donvale and Hawthorn. They are expected to be charged by summons. The police investigation is ongoing.
It is believed the vandals' party got out of hand and they attacked several conservatory windows, garden furniture and left behind overturned shopping trolleys, rubbish and debris both inside and outside the 1990 building.
The party appears to have gone on for several hours with vandals taping together two long lines of empty beer cans, starting with expensive foreign beer, Bavaria Premium, before adding cut-price Toohey's beer Red Bitter.
Friends of St Kilda Botanical Gardens co-convener Judith Smith said vandals had smashed windows on two sides of the conservatory and had vandalised inside.
"It is just devastating — big windows and little ones all broken — it is significant damage," Ms Smith said.
She said the gardens were regularly attacked overnight and the two glass houses used by the gardening group were often vandalised.
"They smash the windows and wreck the place inside. Sometimes they steal plants, which aren't worth much, and you wonder why they would bother," she said.
Ms Smith called for greater security in the gardens saying they were often unlocked until well after dark rather than by sunset. She said Port Phillip Council had plans to replace the gardens' fence.
"There is far too much vandalism in the gardens and it is ongoing," Ms Smith said.
Ms Smith also called for local residents to report disturbances in the gardens to police.
The gardens are run by Port Phillip Council. A gardens' spokesperson was not available for comment.