If ever there was a summer to elevate drought-tolerant gardens to the top of the landscaping agenda it was this one – widespread hosepipe bans, wildfires in Europe and the UK, and temperatures regularly hitting mid thirties have meant those Mediterranean gardens that were once the preserve of Greek holidays are being touted as the answer to all our horticultural prayers. These are gardens that are made up of shrubby aromatic plants planted in gravel that are adapted to develop deep roots to seek out limited water resources, and thus can hack months of punishing temperatures and little to no rain without so much as a flinch of a silvery leaf. It’s tempting to suggest we all gravel our gardens and watch our water worry dissipate, but as with all quick fixes, there is often a hidden cost – or two.
The first is environmental. Many of the gravel gardens we hold up as poster girls of the genre are product of their physical environment not just the weather. Traditional Mediterranean gardens are borne of naturally poor fertility soils, and rocky cliffs where nutrient-rich soil is not available. Beth Chatto, the original OG in the UK created her gravel garden on an old car park, a demolition site. Her approach grew out of a very English instinct: work with what you have, choose plants that want to be there, and let the garden tell you what succeeds. The gravel garden, in this sense, is a descendant of the cottage garden ethos — resourceful, plant-led, unfussy about appearances. However most of us don’t have gravel and car parks, we have soil, which contains masses of microbial and insect life, not to mention providing vital carbon sequestration services. Adopting wide-scale gravel gardens without thinking about what we’re displacing, and also where we’re sourcing our replacement substrate from, is anything but resourceful. But that’s not to say they’re off the menu.
We adopted a half-half approach in a project earlier this year – mixing existing building waste with soil already on site to create a more free-draining garden that would support more drought-hardy plants that in turn need less water. It’s been a punishing first year for this young garden but the results have been fantastic – however not without maintenance. What we have gained in water reduction we have not lost in other areas – the higher soil content has meant vigilance with weeds has been almost as intensive as with a ‘traditional’ garden.
Charlie Harpur manages the Walled Garden at Knepp, a pioneering project in Sussex where the principles of rewilding are being applied to a more domestic setting. He has been tracking exactly how much labour different planting regimes actually require — and the results have revealed the low maintenance promise is complicated. Comparing beds across a range of soil types, Charlie has found that the relationship between fertility and effort is far from straightforward. Poorer, free-draining substrates built from crushed rubble and sand needed under five minutes of work per square metre a year, and supported a striking diversity of fifteen to twenty plants in that space. While the rich, organic soils needed even less time they also supported far fewer plants competing for the same ground — proof that low effort and high diversity don't automatically go together. As Charlie puts it, the guiding principle remains simple: ‘you get out of a garden what you put into it’ and gardening without water doesn’t mean gardening without effort.
Crucially, Charlie's experience at Knepp also shows that the drought itself doesn't remove the gardener from the equation — it just changes the job. The work shifts from watering and grooming to a kind of garden triage — observing which plants are struggling, understanding why, and deciding whether to help them, relocate them, or let them go. Even in drought-tolerant gardens that're designed from the outset for resilience, drawing on more than a thousand species selected to cope with climate extremes, sustained heat still creates casualties – around 30 species have needed a life-saving watering-can intervention to survive an unusually punishing summer.
Even this level of life-saving would be considered soft in the tough-love world of Patrick Clarke, a designer who has built his own drought-tolerant garden in the south of France. Patrick has arrived at a similar conclusion through nerve-holding and self-discipline rather than data. Gardening through summers that regularly top 40 degrees, and being present for only half the year, Patrick made an early decision to rely on nothing but rainfall. ‘You have to be prepared to be hard and fast and determined to ensure that your garden truly is drought tolerant (a sneaky use of the watering can is not an acceptable action) and accept that plants will fail along the way, while those that stand the test will grow up big and strong.’ The results, he says, are a garden of ‘rich greens and soft silvers’ and ‘relatively’ low maintenance. Because unwatered plants send roots deep and wide in search of moisture, they grow ‘sturdy, burly and robust,’ which means the pruning workload ends up much the same as in a conventionally irrigated garden. What genuinely drops away is weeding, since thirsty conditions keep weeds from thriving, and of course there's no time spent standing with a hose.
For those of us not living in the South of France or with a carpark of crushed concrete at our disposal, there are other ways we can help build resilience in our gardens – looking to the native plants that are still thriving in hedgerows fields, such as Achillea, Knapweed and Wild Carrot and weaving them into schemes, as well as planting trees in our gardens to cast shade and protect our soils – and then sitting under them with a cold iced drink.
