What the Changing Climate Means for Garden Design

Wetter and drier, hotter and possibly colder – and windier too – that contradictory mix appears to sum up the predictions for the UK over the rest of the century. It seems that just when the British climate can’t get any stranger, it does!

Britain’s weather has always been what the more charitable tourist guidebooks have described as ‘changeable’ – but now, that’s no longer simply on a daily basis. According to the Met Office, while globally, the planet has warmed by around 0.75°C over the last hundred years, and generally the world’s wetter places have become wetter, and the drier ones, drier, regional differences are apparent too, especially seasonally – and that means still more change for us.

Britain’s challenge

After the events of the last few years – heavy snow, plummeting temperatures, heat waves, wind-storms, flooding and drought – few of us need much convincing of that, but even aside of such freakish extremes, for gardeners especially, the new ‘normal’ of Britain’s climate will be a challenge.

The growing trend of decreasing summer rainfall will inevitably increase the chances of drought and hosepipe bans, while more winter rain brings with it the associated risk of flooding – and not necessarily just for those areas historically threatened.

At the same time, the growing season itself is changing. Despite those occasional anomalous years when winter clings on long beyond its time, Met Office records show a general pattern of earlier springs, and later autumns – and that is having an effect on wildlife too. As everything from frogs and toads, to bees, butterflies and birds shift the pattern of their activities, the age old rhythm of natural pollination and pest control also changes.

Gardening and garden design in our changing climate is clearly going to have to be a bit different.

Hotter, drier summers

Periodic – and potentially even fairly routine – summer drought, is one of the most likely scenarios to face British gardeners into the century, and beyond the purely climatic aspects of water shortages, the increasing demand on local supplies is set to be a major sustainability issue in the coming years.

Drought proof gardens are shaping up to become standard elements of homes, as future generations of gardeners and landscapers make more use of water conserving features, drought-resistant planting schemes, and rainwater harvesting systems.

Water saving

When some 780 million people – roughly one in nine – of the world’s population lack access to proper drinking water according to the 2012 joint study by the World Health Organisation and UNICEF, it is hard to justify pouring gallons of it onto plants, however keen a gardener you may be!

Grey water and irrigation systems for new builds

Collecting rainwater is, of course, as old as gardening itself, but as summers become drier, and hosepipe bans more commonplace, increasingly sophisticated systems to harvest what little rain does fall are likely to join traditional water butts as regular features in gardens. The case for grey water recycling too will almost certainly get a boost, for both new builds and as a retro-fit to existing housing, for irrigation and other general garden purposes where there is no particular necessity to use clean, potable (drinking) water.

Some have called for legislation to drive greater uptake of these types of systems, but in the long run, this might not actually be necessary. Self interest and the falling cost of equipment may well be enough to persuade most, if not all, householders of the benefits for themselves.

Drought resistant plants

Ultimately, having a successful garden in the changing summer climate will inevitably fall on the proper selection of plants – and the good news is that there are plenty to choose from, and most local garden centres already boast a sizeable selection. British gardeners have always been ready to experiment with foreign species – witness the vast treasure trove of plants originally brought back by Victorian collectors which now form the mainstay of the average suburban garden’s planting.

Mediterranean species typically feature predominately on the list, although there are many suitable, and often showy, examples from many of the world’s warmer, drier regions, including Australia, New Zealand and South Africa. Just a few of the suitable candidates to be seen include:

  • Thyme (Thymus)
  • Oregano (Origanum)
  • Lamb’s ears (Stachys)
  • Wormwood (Artemesia)
  • Pelargoniums – a long-established British favourite
  • New Zealand flax (Phormium)
  • Cabbage Palm (Cordyline)
  • Yucca – especially Y. filamentosa or Y. gloriosa
  • Thrift (a UK-native coastal plant, also known as sea-pink) – Armeria

There’s good news for the vegetable gardener too. Although there’s a growing number of unusual and non-traditional veggies on offer, some of the old established favourites will also cope surprisingly well with low rainfall, especially once established:

  • Spinach beet – arguably the most drought-tolerant ‘leaf’ crop of all.
  • Carrots
  • Leeks
  • Onions
  • Parsnips

Design for flooding too?

Dealing with the effects of contradictory climate change – such as the ‘floods and droughts’ predictions for the UK – often introduces conflicting necessities into landscape design, and reconciling them isn’t necessarily easy.

The current avoidance of paving over front gardens to provide hard standing does, for example, go a long way to reducing the contribution of surface run off to the urban flooding risk when the heavens open, but plant the same space, and when the rains don’t fall, the result can be an arid and unsightly mess.

Ground cover and gravel gardening

One solution is densely planted ground-cover, using species such as Rose of Sharon (Cistus), Lavender (Lavandula) and Rosemary (Rosmarinus) for instance, which will help shade the soil and so reduce water loss from the surface by evaporation – and the likelihood of wind erosion too.

A gravel garden can also provide an effective alternative method, particularly if there’s a need to design a low-maintenance scheme that requires very little attention to keep it looking good. Contrary to what some of its critics might say, the gravel garden isn’t, however, just an easy way out, and it is far from a “lazy gardener’s approach” to create.

The trick is to prepare the ground well:

  • Opening it up if needs be, to ensure that the underlying soil is free-draining – which obviously helps mitigate those surface run off risks
  • Removing any perennial weeds that may be present
  • Then laying a good quality, perforated ground membrane.

By carefully selecting the top layer of gravel used, there’s plenty of scope to be as artistic as you want, and a well crafted gravel garden can be a useful solution to the drought/flood conundrum, without detracting from the personalisation of your property, or greatly limiting its amenity value.

Physical protection

Casting a critical eye over your particular patch of land has always been a major part of successful gardening, and if anything, it will become even more vital as our climate shifts. Knowing where water is likely to collect when it rains, or dry out when it doesn’t, where winds will buffet and dips and hollows will be prone to frost allows you to plan your planting and features accordingly – and not just for today’s conditions.

Providing physical protection – either via hard landscaped elements, or as moveable objects – is one aspect of gardening that some people believe is likely to take on growing importance over the coming years, particularly to help deal with any unforeseen extremes of weather. The possibilities are almost endless – largely dictated by the location of your property, the likely risks to which it may be exposed and, in no small way, your own ingenuity – and include a range of possible elements such as:

  • Wind-breaks/wind-proof fencing
  • Waterproof garden walls
  • Raised beds, ponds and water features
  • Path and driveway gullies – to channel water safely away
  • Patio door flood protection
  • Temporary or permanent shading – to reduce evaporative water loss during drought

Facing the future challenge

British gardens have always been challenging places – even the best of our weather makes sure of that – but they now face change on a previously unprecedented scale. According to research undertaken by the National Trust, spring has arrived between two and six days earlier, and the start of autumn has been delayed by two days on average, each decade for the last half-century, and that general trend seems to be showing no signs of stopping any time soon. While this means that the growing season is lengthening, the shifting rainfall pattern that comes too almost certainly represents the single most serious impact of climate change for gardeners – and it is likely to have a major effect. Met Office predictions suggest that the average annual moisture content of British soils could decrease by up to a fifth by the 2080s, and possibly by as much as 50% during the summer months. At the same time, aside from their potential to bring flooding problems, the wetter winters could also mean fungal plant diseases will thrive. To face the challenges of the future, gardeners will obviously need to match their approach to planting and management to the changing conditions. It’s probably a good job, then, that Britain’s gardeners are quite such an adaptable bunch!