How Can a Historic Garden Adapt to Climate Change?

Gardens are one of England’s essential iconographies: living, lasting testaments to the intimate relationship between people and nature, not to mention a kind of aesthetic mainstay. But climate change is altering everything that helps them thrive. That some of the country’s most enduring gardens are facing critical threats to both their identity and their existence raises questions not only of how to respond pragmatically — be it by relocating the azaleas at Cliveden House in Berkshire and replacing them with lavender, or reinvesting in the Grecian garden at Sissinghurst Castle in Kent — but of what makes a storied garden storied in the first place.

Never have these questions seemed more pressing than this past summer, tied for the country’s hottest on record, with temperatures above 100 degrees Fahrenheit. At Oxburgh Hall, a red brick estate built in 1482 for the Bedingfeld family in the East Anglian countryside, “all of the grass was brown and dead and seared, not a lick of green,” says Dea Fischer, the estate’s senior gardener. Yet other sections of the Parterre, a 9,000-square-foot French-inspired garden just beyond the manor’s moat, told a different tale.

First laid out for the sixth baronet in 1848, the Parterre was traditionally planted three times a year to match the Bedingfelds’ heraldry: a red medallion amid a field of blue and yellow. “Loud and proud,” says Fischer. “It was a signature display of wealth.” (After the National Trust conservation charity took ownership in 1952, the cycle was scaled back to once per year.)

But lately, Oxburgh Hall had been contending with relentless heat, as well as droughts and downpours. It’s a fickle combination that only a particularly hardy and resilient plant can endure, and sudden floods wash away the crisp edges of the Parterre’s intricate design.

In response, Fischer began experimenting with new plantings. But because the garden belongs to the National Trust, she was also limited in her decisions. “First, we must use the original biological material,” she explains, citing Pelargonium ‘Paul Crampel’ — which has been propagated from mother plants at Oxburgh since Victorian times — and Canna indica ‘Indian shot’ as varieties that give the Parterre its red hue. If that’s not feasible, “we need to provide the same plant,” genus and species from another source. Then, she continues, “we must provide plants that were available to gardeners of that era. If we can’t do that, our final choice is to use plants that have an appearance that’s in keeping with the style that we’re trying to preserve. That’s where we are now. Things that used to grow here just won’t anymore.”

Last year, she introduced Sedum rupestre ‘Silver’ to four central beds in a crucial test: How would this succulent-like stonecrop fare in increasingly extreme conditions? “They transformed almost overnight with yellow flowers that were just humming with bees for weeks,” she says. “It was thrilling to witness.” By August, the beds were in full bloom.

By switching from annuals to perennials — the sedum, as well as Alyssum montanum ‘Mountain Gold,’ with its “sweetly scented yellow,” and Ajuga reptans ‘Braunherz’ and ‘Black Scallop’ for their “spikes of intense purple-blue” — Fischer hopes to eventually make these beds “a solid mass of vegetation,” she says, “filled with foliage color [or] flower color year-round.” No more winters where the area’s characteristic light, sandy soil is left exposed to the elements; no more waiting for seasons to shift to bring back life. The evergreens will also act as a carbon sink, locking in nutrients and moisture, while safeguarding against erosion. As part of a four-year plan to fortify the garden, she’ll also rip out box hedges plagued by fungal blight and, inevitably, moth caterpillars, both of which have thrived in the warmth, and replace them with 6,000 Euonymus japonicus ‘Microphyllus’ that have “no known pests or diseases. For now.”

But is a historic garden with new flora still the same garden? A survey cited in a 2017 report by Britain’s Royal Horticultural Society indicates that “one in five respondents would no longer visit” certain gardens if their “character altered as a result of climate change.” As we confront a range of disruptions to the landscapes in our lives, there is perhaps something especially distressing about witnessing sites that are by design considered timeless undergo transformations. Except that gardens’ characters are continually being altered. The modern Parterre at Oxburgh Hall sits on the footprint of a parterre that dates to the 17th century; trying to replicate it would be impossible, as too many details have been lost to the ages. During World War II, the entire expanse was scrapped to make way for potatoes; Fischer still regularly finds stray spuds nestled among the ornamentals. Perhaps what makes a garden a garden is not what’s planted in it at any given moment but how it’s planted — and the fact that, year after year, someone has been devoted to keeping it alive. “A gardener,” says Fischer, “was doing what I’m doing 500 years ago.”

source: nytimes.com