Two Japanese Black Pines - pruned with the same techniques as bonsai, just on a larger scale - have been recently planted at the National Arboretum Canberra.

The 62-year-old trees, each weighing a couple of tonnes, were donated by a pioneer of bonsai in Australia, 82-year-old Dorothy Koreshoff, who imported them from Japan as seeds with her husband Vita in 1951. ''They're the oldest black pines in Australia, I can assure you,'' Mrs Koreshoff said from her home in Quorrobolong, south of Cessnock, in the Hunter Valley.

''There were no Japanese pines in Australia at that time, so they were the first ones imported into Australia.''

Mrs Koreshoff originally donated the trees in 2008 to the National Bonsai and Penjing Collection Australia's temporary home at the Caretaker's Cottage in Commonwealth Park. They were transplanted to the arboretum near its new bonsai pavilion last week.

National Bonsai and Penjing Collection of Australia curator Leigh Taafe said the pines would usually grow to eight to 10 metres high but with some bonsai-style pruning they were trained to about 2.5 metres high.

''They're significant for their age and for Dorothy's status in the bonsai community,'' Mr Taafe said.

The trees - as seeds - had a rough start in Australia, subject to some bureaucratic red tape and left languishing for at least several months in a Customs office in Sydney.

Mrs Koreshoff said she was ''chastised'' by Customs for bringing in a pound of seed from several tree varieties from Japan without a licence.

''Well, we were just a backyarder back then. We didn't have a licence,'' she said.

''We were taken up to a second floor and they said we should not have brought these in and it was against regulations not to have a licence for them. 'But they're here,' the officer said. The window ledge was at least 30cm wide and he placed the box [of seeds] on it and I guarantee it didn't move. That was in May and in August the box arrived by post. It hadn't even been opened.''

The trees were initially grown in sandy soil in Maroubra and then moved to the Koreshoffs' family nursery in Castle Hill in 1966 where they remained until 2008 when the nursery closed. She wanted them to go to a good home so donated them to the collection in Canberra.

''I couldn't sell them, I wanted to give them away,'' she said. ''I just love working with the bonsai, love it. It's my life.''

Mrs Koreshoff was introduced to bonsai by her husband Vita who was 21 years her senior and died in 1985 - ''the greatest loss of my life''.

''He was already doing bonsai when I was born,'' she said. ''I got married when I was 18 and from that time on I was as devoted and enthusiastic as he was. I had an artistic background and wanted to be an artist, well, I'm an artist all right, I'm a horticultural artist.''

She believed the trees would thrive at the arboretum.