Of all the things you might amass, trees would have to be one of the most unwieldy. They take up space and they soak up time. It's not a pursuit for the restless. But it's hard to keep a good tree collector from grouping trunks and canopies, foliage and flowers. Their plantations spill over hectares and change with the seasons.

In 1838 the pioneering Scottish botanist and garden designer John Claudius Loudon came up with a name for such a collection: "arboretum". The term stuck.

By CBC Radio

When David Milarch first learned about ancient coast redwood stumps hidden in California, he says he was "the most thunderstruck" he'd ever been. At about 10 metres in diameter, he'd never heard of any tree growing that big. Now the non-profit that Milarch co-founded is using genetic information from five massive tree stumps to help in the fight against climate change.

On Dec. 14, the Archangel Ancient Tree Archive planted 75 coast redwood saplings at Presidio, a park in San Francisco, that are exact clones of those stumps.