Scrap metal dealers are being asked to keep watch for a number of bronze plaques stolen from Wellington's Botanic Garden over the past week.

Photo: Supplied

Botanic Gardens manager David Sole said it was noticed today about six or seven were missing, but it would take a few days to check the entire garden.

"There could be more, there's dozens and dozens of plaques in the garden so it'll take us a while to get around them all," Mr Sole said.

He said the plaques were from a World War I artefact, a sculpture, and off memorial chairs.

"There was four taken from the Krupp Gun, an antique artillery piece which was put up the top by the cable car in 1999. It was a major restoration exercise and four plaques were put in place to describe what the gun is and who the donors were, and who funded the restoration."

Plaques were also taken from the Rudderstone sculpture and off a number of memorial chairs, some of which were donated.

"People come to us, perhaps someone who's about to pass away or members of their family and say they'd like a memorial seat and they will purchase the seat and on that seat is usually a plaque," Mr Sole said.

"They're pretty special for those families and for the garden and families come back to sit on the seat and contemplate so it's particularly tragic that those ones have gone."

Photo: Supplied

Mr Sole said the scrap metal value was not worth much, but could cost up to $10,000 to replace because of casting costs.

"The dealers tell us the metal is not worth very much, the value to us is in the casting and the casting process," he said.

He said security was difficult due to the size of the gardens, and cameras were not in place.

"We rely on the public, they are very good and let us know what's happening pretty quickly and we're hopeful we get these plaques back," Mr Sole said.

"They represent our cultural history, our people's history and a piece of our military history so you're not just taking stuff from the garden, you're taking stuff from the people of Wellington."

The police have been notified.