Seeds of the national floral emblem have returned to earth after a six-month visit to the International Space Station for experiments.

"This is one small step for golden wattle but one giant leap for biosecurity science and innovation," Agriculture Minister David Littleproud said on Wednesday.

Working with Japan's space agency, Australian scientists sent the seeds into space last year on a Space X rocket.

"Biosecurity officers will now inspect the well-travelled golden wattle seeds to ensure that they meet biosecurity requirements and have not picked up any exotic pests and diseases on their journey," Mr Littleproud said.

Australian school children will plant the golden wattle after the precious cargo is checked, as part of the Seeds in Space education program.

Some of the space seeds will also be planted in the Australian embassy garden in Tokyo.

Australia's science agency CSIRO collected the seeds from a wild population in Victoria as part of a national research collection that safeguards millions of specimens.

Australian Associated Press