Gardens are time-capsules.  I don’t just mean the odd, poignant occasion when you dig up a bone carefully buried, long ago, by a dog you never met. I mean the fashions in plants that date gardens just as surely as winklepickers, blue eyeshadow or shoulderpads date photographs.  As you walk round the suburbs you’ll see  jacarandas arching over Californian bungalows, rows of red cordylines hemming eaveless McMansions, 70s brick veneer hidden behind shaggy bottlebrushes and rambling grevilleas.  Social history has roots in the backyard.

Our place was built in the late 1950s, and I reckon a few of the bigger trees date from about that time.  The largest hibiscus I’ve ever seen, entwined with an ancient honeysuckle as weighty as a strangler fig, reaching up above the roof of our neighbour’s two-story house to catch the light, speaks to me of post-war dreams of expansive America, a Hawaiian fantasy.  The liquidambar and the Japanese maple – a yearning for colour in the fall.

A fossil in the garden

Until today, I put the tallest tree in the yard in the same category – I figured it was a swamp cypress, native of the Everglades, happy knee-deep in water (and, with enough water, they do grow knees!).  Like a larch, it’s a deciduous conifer, needles turning copper in the autumn, then returning, fresh and feathery green in the spring.

But I was wrong.  It’s not an imposing American, though it is a cousin of the great sequoias.  It’s Metasequoia glyptostroboides, a dawn redwood: living fossil from the “dawn of time”.  It’s the Wollemi Pine of the 1940s.   An expedition to a remote village in Szechuan province in 1946 discovered a giant living Metasequoia, a species known from fossil evidence to have existed for 100 million years, thought to have been extinct for at least two million more.

Metasequoia (“sort of Sequoia”, “Sequoia-ish”) was something of a sensation in the late 1940s. In 1948 Sydney’s Royal Botanical Gardens, along with arboreta all over the world, received seeds and commercial nurseries in Australia began growing them for sale the same year. With seeds both easy to collect and propagate, the dawn redwood, George Seddon says, was a big money spinner and the trees are are now common in parks and gardens all over the world, from the subtropics to Alaska.  It’s proudly grown as a street tree in China, though it is critically endangered in its only location in the wild, Metasequoia Valley, not far from the staggeringly huge Three Gorges Dam, a hydro scheme so big filling it slowed the rotation of the earth.

Now of course, I want more lazarus taxa – more trees returned from the dead.  Gingko with its maiden-hair leaves, a clear yellow in the fall.  Okay, it has fruits that smell of vomit and its edible nut is toxic.  Who cares! It’s a dinosaur tree, over a hundred million years old!  As is the Wollemi Pine – three clumps of genetically identical trees discovered in a deep, remote canyon in 1994 – weird looking, self-coppicing, lusted over by others in possession of dawn redwood, it seems.  Although John Benson of the Royal Botanical Gardens in Sydney advises against hoarding this fossil: “people who put them in their backyard will soon have no backyard” (Seddon, 2005, 100).

A fossil in the garden

My neighbours say every winter they look out their window and think, hearts sinking, that the redwood tree we share has gone and died.  Perhaps I should reassure them that it will live for more than a hundred years; that it is Lazarus, come back from the dead; that it has been around for a hundred million years.