Stop digging – and burn your books. The end of the world might not yet quite be nigh but, according to recent reports, the end of spring, as we know it, is. In the UK, the Royal Horticultural Society (RHS) has said that authoritative gardening tomes might now be out of date, since spring planting times are creeping further back into winter. In the US, the non-profit National Arbor Day Foundation has redrawn its hardiness zone map, moving many states into warmer planting zones.
For many people, the garden will be the stage upon which climate change plays out most dramatically. And gardeners around the world are hungry for information. In a few weeks the New York Botanical Garden is holding a series of symposiums and public programmes, with an impressive line-up of speakers, on gardening in a warming world; the RHS meanwhile is preparing for a flood of calls to its inquiry line as things heat up.
Boon, though, or bane? The fertile gardening blogging scene reflects this dilemma of how to react to climate change. Should you don a hairshirt and bemoan mankind’s meddling with the seasons? Or, in the words of one blogger, Michele Owens, on Gardenrant.com, join the “fiddling-while-Rome-burns camp”? She describes “delighting in every moment of [the] peculiarly warm winter and making bold plans regarding magnolias and sweet cherries”. “Hey, you cynical and self-serving auto and power industries,” she adds, “we . . . gardeners owe you one!”
Apocalypticism descends readily upon the climate change debate but the likelihood is that a sultrier planet will be both a boon and a bane for gardeners – depending largely on how much longer they will spend on it. Kevin Harrison, who teaches environmental policy at McDaniel College in Maryland, US, suggests simply swapping gardening almanacs rather than shredding them wholesale. Because North America, unlike Britain, consists of numerous climate zones, his practical suggestion is to “apply Virginia’s gardening book to Maryland, New York’s to Boston and so on . . . Everything just shifts poleward. Commercial gardeners have known about this for years and started making the change this fall.”
The RHS also counsels against comprehensive book-burning (or mulching, to be environmentally sound) in the short term in favour of interpretative reading. “Gardening hasn’t changed for hundreds of years,” says Guy Barter, the society’s chief adviser, “but over the past few decades the ends and the beginnings of the seasons have moved, so some crops can be sown and harvested a little earlier than is said in the books.” Gardeners should take advantage of such conditions, he adds. “The growing season’s longer, there’s more light, more warmth. Vegetables like squashes and sweet corn, and fruits like nectarines, figs and peaches, will all grow much better in the longer growing season and with the higher temperatures that we’re going to experience.”
Still, as climbing temperatures suck moisture from the soil, the burgeoning problem worldwide will be finding enough water to bring such crops to fruition. By 2050 in the UK, Barter says: “It’s likely to be so darn hot in the summer that pines will be the best trees to grow because they’re so much more drought-resistant than broad-leaved species.” A report from the UK’s University of East Anglia paints a hellish picture of this period, with marauding wasps buzzing amid thickets of Triffid-like weeds and the withering of such symbolic English species as the rose.
What, then, to do? First, gardeners might need to become water misers, hoarding the precious resource – no doubt the bounty of future wars – for the harsh summers. Barter sees the gardeners of the future using “sophisticated, high-tech irrigation systems to make use of every drop of water they can lay their hands on”.
Go native is another common cry from advisers eyeing the heat shimmer on the horizon. Native plants are, in a sense, themselves no longer native when their habitat decamps towards the equator, but, says Marcy Marsden, one of a team of scientists collaborating with former US vice-president and environmentalist Al Gore, “native plants at least have some affinity with the area, whereas cultivated ones will be even harder to grow in the backyard garden.”
Trees, in particular, press home the need for climatic aforethought. “You plant a tree for your grandchildren, not yourself,” Marsden says. Predicted water shortages and higher temperatures 50 years hence should affect the tree species you plant now. “You need to look to what’s native and hardy under warmer conditions,” she says. In her home state of Texas, on the edge of the US great plains and eastern forests, for example, “drought-tolerant oaks – scrubby, thin-stemmed, lower-growing oaks – as well as good shade trees”, such as the water-scavenging mesquite, are best.
Gardens have an intrinsic role to play in protecting the future environment. They soak up water from brief, furious winter inundations, for example, thus diminishing the amount of urban pollutants sluiced into the waterways. But gardeners can do more – should they wish to – to keep the Earth only simmering.
Take, for instance, the lawn. These “monocultural components of the suburban ideal touch upon so many aspects of global warming”, says Deborah Snoonian, managing editor of US environmental magazine Plenty. They hog water, they need CO2-belching mowers to keep them respectable and they hook the garden, like a barbiturate- smoothed housewife, on pesticides and herbicides – energy-guzzlers in their manufacture and distribution – when it could establish a natural homeostasis in their absence. Her advice? Dig it up or let it run rampant.
So does a warming-world garden imply a different aesthetic? It does. By force of legislation and conscience, the gardens of the future are likely to be wilder in both senses of the word. But form follows function and, in Snoonian’s words, climate change should cultivate “a redefinition of the beautiful garden to mean a beautiful natural space outside your home”.