Terri, Bindi and Bob name tree after Steve BINDI Irwin has named a special Adelaide gum tree after her late father Steve.

Bindi, Bob and Terri Irwin today planted the tree outside Adelaide's Botanic Gardens as part of a four-day visit to South Australia.

The high-profile environmentalists and family of the late wildlife campaigner Steve Irwin have visited several local tourist attractions, including Adelaide Zoo, since arriving on Sunday.

Terri is in SA to speak at the Environment and Heritage Department's Stirring the Possum environment forum tomorrow night and extended her stay to enjoy the sights.

Today, the family joined Premier Mike Rann to plant a river red gum in Botanic Park as part of the State Government's Three Million Trees program.

It was the 1,500,000th tree to be planted under the program to combat climate change and protect biodiversity since it began in 2003.

Mrs Irwin said Bindi and Bob were "expert tree planters" and they were all excited to help the program.

"We are seeing things in South Australia like drought and water levels dropping and the need for preservation and trees are directly linked with that," she said.

"You don't need a lot of time or money to do this kind of initiative."

Bindi said she would like to name the river red gum "Steve the Tree" after her father.

"I love trees, I especially like climbing trees, but this one might need to grow a bit," she said.