Retired Lagmhor farmer and conservationist Russell Langdon is still building a legacy, while looking back on milestones.

Langdon put a bulldozer through the blackberry along a kilometre stretch of land bordering the south branch of the Ashburton River 20 years ago, and planted several hundred acorns.

The maverick conservationist reckons between 300 - 400 of the acorns took.

Fast forward 20 years and Langdon has an oak-lined avenue not far from the water's edge.

"It's a great place to come on a hot windy day. It shows what you can do with wasteland along the river."

The acorns are also a good food source for wild turkeys, pheasants and peacocks, Langdon said.

There's a release pen for pheasants a short walk down the cool, shaded grove. Langdon has a funny story about that. Not long after the pen was built the police descended on the property thinking someone was "growing dope there".

Langdon has also planted some conifers and redwoods along the river. He reckons people will come to admire the huge redwoods in 100 years.

Now in his 90s, Langdon is still working on his wetland reserve just back from the river. The sanctuary at Riverbridge started as a millennium project and is the reason Langdon was awarded a Queen's Service Medal in 2006 for his conservation work.

Next week he plans to fill his old vehicle with plants for another round of native planting on the QEII site.

"It's better to wear out than rust out," he quipped.

He's particularly proud of his brown teal breeding programme.

It's the fourth-most endangered water bird and Langdon doesn't understand why more people aren't interested in the nocturnal birds.

"They poke around the paddocks at night and are vulnerable to cats," he said.

By Sharon Davis