Landscapes are all about creating micro-climate, or would be, if designed for that goal. Why is this important and what do I mean?
Almost all life is contained in a thin crust of soil, a wedge of atmospheric gases, and water. Plants are the principal medium that interacts with and regulates all three. Absolutely nothing else does this as well, or at all; think about it.
The way we organise our plants in our urban landscape will determine how well this interaction occurs, how successful it is. Yet I have never heard of a single project that has been developed with this understanding and this goal in mind. With climate change, we urgently need to re-think the way we design our landscapes, and why we design them. Whilst all the human-centric design reasons will always hold true, we need to layer into our thinking this new understanding of how plants interact. To build new ecologies, new ecosystems, we have to design for plants to actually function, rather than just look nice. For when they do this, our environment literally comes alive. More importantly, they might just, if done on sufficient scale, save us from ourselves.
When I use the word treescapes, I don’t just mean trees and grass; we’ve had that for years in the form of parks, and in their traditional form, they’ve done little for us. No, our designs need to build up layers of living material – biomass, for with biomass comes moisture entrapment, shade, food for insects, etc. Think of it in terms of height and depth of microclimate. How much depth is there in a stretch of irrigated grass, maybe 50mm above ground, 200mm below? No species variation, so what we have is little more than a green desert, albeit one that can hold bit a of moisture.
Trees in paved streets are also less able to generate micro-climate, but they are a bit of an exception, as they provide shade for people to walk under. Where width allows, even here we should layer our planting.
If we replace that grass with a range of groundcover plants – not a monoculture – you begin to get a little more variation; different root structures and depth, different foliage shapes, height, form and flower. More variety, more microclimate, more food source, more ecology. Looks good too.
Next we add shrubs and suddenly we are into an new realm, that of woody plants (I’m being simplistic here, many groundcovers are of course woody). Shrubs create three-dimensional space with their frameworks, within which micro-worlds reside. Deciduous plants shed their leaves, as do evergreens, and this begins to build leaf litter – mulch. Don’t tidy it up! We need ecologies in that soil, and microbes need food. Our obsession with tidyness has a lot to answer for. Suddenly, we have height in our micro-climate, three-dimensional form. We humans (for we scale everything according to our own height and perception) can walk amongst these plants, take part, interact. Our microclimate is now two metres high, maybe more. But something is missing and it’s still too hot…
Trees! Now we have a game changer and our micro-environment just became vast, in relative terms, maybe up to 30 metres, though 10-20m may be more average. We now have true diversity of shape, height, leaf, flower and roots. We have shade! Under trees it may be 10°C cooler and we love it. Plants love it too. Moisture now gets retained within the human habitable zone, fungi and microbes thrive in soils, insects and birds abound. This is our urban jungle and we need it. The planet needs it. This tiny sliver of crust we live on can be rich, abundant, in every climate and every place, if we put our minds to it, if we have the will. And when the planet becomes searing, creating livable environments with trees of any type, may be the only thing that keeps us alive, unless we become troglodytes.
This is the next level of landscape design, the new challenge; creating future ecologies and environments that matter, that keep us cool, that give us resources and soothe our souls. We will create new (novel) ecologies that fit the changing environment, trans-migrating parts of ecologies that once lived elswhere. In that place they may be dying out, as might your local ecology. If they now fit where you live, that’s where they need to be. In turn, that place of origin may itself need to adapt and change. In all things and all places, we need microclimate, shade and soil.
The other side of work I undertake in the Middle-East region (other than tree consultancy) is planting design, for creating new landscapes always brings me a special joy. When they are in public spaces, I love the chance it gives to interact (albeit remotely) with many people in place, over time and hopefully, enhance their enjoyment of that place. In the public realm, what that place is, is being questioned and challenged in the light of urbanisation and climate change. Ecology and environment are driving design as never before.
I am about to start working on a collaborative project in Saudi Arabia. It will involve the specification of many trees, shrubs and groundcovers and I get to find out just how many locally-sourced big specimens I can find that are of acceptable quality. Much of this will come down to the application of formative pruning in the nursery and I’ll be on the lookout for the best available in the region. I suspect I’ll be sourcing a lot from neigbouring UAE, simply because of familiarity of sources. Quality remains a challenge, though.
My most pressing concern I have is how to improve on irrigation techniques, which are traditionally massed surface drip lines onto marginally improved sand. This is inefficient and wasteful and I shall be looking at the use of moisture retention mediums and sub-surface irrigation. I believe most watering of landscapes in arid climates could be cut by half, just by more efficient application and retention, in the right place. The picture above shows typical wastage in a Dubai suburban landscape.
Whilst urban planting requires urban plants, I will also be looking at the use of more climate-adaptive species, which I think is important in an era of climate crisis; the Middle-East is going to struggle to cope with every degree of temperature increase. The use of more desert-adapted planting is not new, and not applicable everywhere but I believe there is much scope for experimentation and new thinking.
For me, planting design is about building communities, layering types of plants together in harmonious associations that fit. I don’t mind grouping plants together that come from different geographical regions, but they have to come from a similar ecological niche. Such design is so much more than just nice foliage contrasts and I believe the results can be subtle, but profound.
Landscape must, of course, fit our purpose but I believe we tend to pursue this end to the exclusion of everything else. Nature is the basis of landscape, and so too is ecology, ecosystem and planet. We should not divorce our landscapes from this reality; rather, they should always seek to remind us of these connections. So yes, in town centres and urban streets, we have our eco-bling landscapes; vibrant places, exotic, heady, purfumed, exciting. Nature at it’s most unbelievably flamboyant (cue pic: delonix, the flamboyant tree). Elsewhere, we need more grounded landscapes, more real, more connected to place.
I love this tree, it is everything I have described above, pure eco-bling. Yet it is not appropriate everywhere and because it has become a part of the standard landscape palette, I belive it is overused, and used in places where other species would be more appropriate. I think there are many trees and shrubs that could be used in the region that haven’t been tried yet, from East Africa, for example. The climate there may be more equatorial and more varied but it is not so remote or different as that of some exotics imported from sub-tropical climates (the Delonix mentioned above is from Madagascar, again not too dissimilar).
I think planting design in the Middle-East faces a whole new range of
challenges and opportunities. The changing climate will force new
thinking, to match the new development and the new understanding that is
emerging of our intimate relationship with nature. I’m hoping to
contribute towards that new expression and understanding.
The world is finally, at the last minute, waking up to the impending effects and consequences of climate change. In the scramble to work out we must do (apart from the obvious cessation of burning fossil fuels), one thing, one factor is looming large: we need to put carbon back into the soil, where it can be stored indefinitely, and we need to reforest the Earth. Much of this is in the agricultural realm but there is a huge amount that can – and must – be done within the landscape and horticultural sectors.
Horticulture has a MISSION, it just doesn’t realise it yet
At the centre of this is good soil husbandry, something that we have largely forgotten about. Modern agriculture bypasses all need of soil health by chemically feeding crops; no need for microbes, nutrients, humus, mycelium or earthworms. Chemical fertilisers and herbicides bypass the lot. Most of our soils now are depleted to the point of useless by chemical farming, exacerbated by the tradition of ploughing, which causes erosion from rain and enables much of the soil carbon to move back into the atmosphere.
So whilst we need current global models of food production to transform into regenerative agriculture and agroforestry, we also need to look at our urban landscapes and gardens, and create a new design ethic, a new paradigm, even. I can’t deal here with agriculture but I have been thinking long and hard on what the landscape and horticulture trades need to do; fortunately, I believe there is a lot that we can do.
We need to envelope our existing horticulture trade within ecology, to create an “environmental horticulture” You could also call it ecological, resilience or regenerative horticulture. We (those of us in the trade) know that as a profession, the training of both horticulture (growing) and landscape (doing) are in decline. Horticultural colleges have shrinking budgets and often get the less ambitious or capable students; after all, who is inspired by the prospect of strimming verges or hedge-trimming another unloved carparking lot? Yet last year’s report by the Ornamental Horticulture Roundtable Group valued horticulture at £24.2 billion in GDP in 2017. That’s not inconsequential, yet it goes unrecognised. Fortunately, there is a way to make it much more enticing to prospective students.
Horticulture has a MISSION, it just doesn’t realise it yet. That mission is to adapt our urban landscapes and gardens to cope with climate change, to mitigate temperatures, water flows, to grow biomass and regenerate soils back to health. Healthy soil is the foundation of life, of all life, including our own. Good soil holds fertility, water and carbon. Yet who amongst us now knows much of soil science? Who designs landscapes as ecologies, as “novel ecosystems”, who chooses plants because they have these abilities, not just for pretty flowers? Who designs plantings for their biomass harvest, for creating mulches to feed the soil?
In this respect, I don’t believe it’s necessary – or right, in fact – to work with native plants only. What is native? What was native? What was here 11,700 years ago when the last glacial period ended and the glaciers retreated? Flora and fauna move around the globe all the time, they are opportunistic, not fixed permanently into some tightly integrated ecosystem. We know there is no “ecological climax”, no ultimate ecosystem for any given place. As temperatures rise, climate zones are now shifting away from the equator quicker than Nature can keep up, although it’ll get there eventually. Maybe we help nature, rather than interfere when we bring in exotic plants that naturalise. Maybe those plants are the start of new ecologies that will adapt to the rapid changes that this climate emergency is bringing us. If plants do well, we need to understand how to enhance and build new ecologies with them. This is how we adapt, how we survive and how we rectify the damage we have done as a species; not by returning to some pristine “before” (which doesn’t exist) but by assisting Nature to heal and adapt. The Earth will do this all by itself, and has done so many times. It doesn’t mind if it takes thousands, or even hundreds of thousands of years to adapt. But we do; we can’t wait that long.
So horticulture needs to stop growing pansies in peat with unrecyclable plastic trays and start sorting out which plants really matter for our future; which ones contribute to new and existing ecologies, which ones are good for biomass, which ones contribute to soil health, which ones give us ecosystem services. We should not enhance one environment at the expense of another.
That’s a very-near future profession of trained eco-warriors, soil saviours, tree patriots and landscape lovers. It needs people who understand soil, who know how to design and use sensors, data and the internet of things, people who see what’s coming and how to mitigate and reverse negative effects, people who really know how to design and install green infrastructure and future automated robotic maintenance systems. Our landscapes can grow food in amongst all the beauty, with urban food forests. We need new knowledge built on old and we need passion, commitment. A wise government would fund this for the returns will be numerous.
This is the enlightenment, that out of dire stress and trouble, we could really learn how to value, connect with and protect this crazy, beautiful world within which we live. Or we can do nothing and watch it all go to hell. I know which I’ll be doing.
The emergence of the idea of resilient planting is a response to a number of different pressures which all have one underlying cause – climate change. Whatever the cause – and I’ll get on to that later – I see it as the most exciting change to the way we design our gardens and landscapes.
Last year we had one of the hottest summers ever recorded and it serves to heighten awareness of the vulnerability of some plants and garden styles to the increasingly erratic climate we are dealing with in the UK. We seem to swing from one extreme to the other, and this is only likely to get worse. I’ve witnessed a number of stressed plants in my own garden but feel relieved that most have thrived throughout the heat, without any watering on my part. this is down to soil, drainage, micro-climate and above all, plant choice.
Ballota pseudodictamnus, a Mediterranean sub-shrub with grey, felted leaves, loved by bees.
We garden on an alluvial coastal plain, and are fortunate to have a very free-draining soil overlying a clay substrate. It gives us fertile soil, great drainage and a moist sub-strata within the reach of most plants (many areas around us are of much heavier clay). A large section of our front area used to be a paddock with a rubble driveway and this now forms the basis of much of my dry garden. Some rubble was removed and topsoil added, but a lot of areas are still rubble-strewn, not unlike some rocky soils. The down side of all this is super-fertility and a soil filled with weed seeds, bindweed and couch. To be honest, I’d have preferred a poorer soil.
When thinking of resilient planting, we have to match our plant type to the environment; we also have to think, long-term, of how our environment might change in the coming years. This is not so important when dealing with short-lived plants such as herbs, sub-shrubs and perennials, but is super important when dealing with long-term structures, especially trees. This is doubly true when we look at the potentially disastrous effects of imported pests and diseases that we are having to content with. Climate change, especially milder winters, mean that exotic pests are happily making a home here and wreaking an unintentional devastation to trees such as our native ash and even oak.
Phlomis russeliana, after flowering. The stem leaves have since dropped, leaving a brown, architectural structure.
No-one can say exactly which way our climate will go as the world hots up; we know we (in the UK) will always be maritime, because that can’t change, but as the Jet stream (wind currents) varies and the Gulf stream (water currents) weakens, we don’t really know what kind of climate we’ll end up with. We can only plan for extremes, and select our planting choices with that in mind. In this respect, the “new perennial” or “naturalistic” planting isn’t necessarily going to be the toughest choice as they come from a continental climate which generally have hot summers and very cold winters. Prairie plants tend to get out-competed here with our mild winters and grasses and forbs that can grow all year round, given mild conditions. The aforementioned fertility (at least in my garden’s case) also doesn’t help as wildflower meadows/prairies tend to have poor soil which helps keep the grasses from assuming dominance. During the heat-stressed weeks, I noticed that where I have perennials like Echinacea and Veronicastrum (in moister areas than the dry garden), they suffered from the lack of water. which resulted in the Veronacastrum flower spikes looking stunted. for more moisture-demanding planting, sub-surface irrigation using harvested rainwater might become a necessity.
To my mind though, if you need irrigation you’re working with the wrong plant-types, trying to grow plants that can’t naturally cope with the conditions that predominate. Save your water for the newly planted and the vegetable plot and for this, consider rainwater harvesting, rather than mains. When selecting plants, see what grows well, both of native and non-native origins and build adaptive micro-ecologies. Our climate is changing faster than the current ecosystems and ecologies can cope with and we need to do whatever we can to build new planting that is of maximum benefit to local wildlife, as well as ourselves.
It’s an exciting time to be a gardener, for there is no place now for the self-indulgence and nature-control-freakishness of the past. What there is a the possibility of co-creating new ecologies that adapt to changes, halt decline and make our local wildlife vibrant and healthy.
Along the way, we can create the most stunning of gardens!
This article was first published in 2007 and has been updated 2018.
Future gardens will be an integral part of a living bio-system that is part house, part garden, an energy conserving and production environment. It will also be a resource for water retention and cleansing, food production area, biomass and environmental haven. Above all, it must continue to be a sanctuary for the soul and from the world at large.
Why do I say this? We cannot consider the future of gardens without accounting for climate change, which is now having a tangible impact on us all. The 2018 IPCC report says we have 12 years left before things reach the point of no return. Whilst there is less talk now about global oil reserves peaking and that energy will be in increasingly short supply, it is still true that we have a long way to go before we have a fully renewable clean energy supply chain. Whatever the outcome, big changes are on the way.
So when we look to the future of our gardens, it’s not so much a matter of what style or vogue will be popular, for such things come and go and in this context are not particularly relevant. You might imagine it is a case of asking what will our climate be like and how will gardens adapt. Yet to talk only of adapting plants to suit the changing conditions is actually to miss the main opportunity for our gardens to become part of the solution to global warming and perhaps, even a core part of our individual – and so collective – survival.
House-garden water capture, cleansing and re-use schematic.
That might sound ridiculous in the face of such monumental problems but I don’t think so. If we all decided to make sure that in our personal lives, we were “carbon neutral” (or as close as possible) then energy demands and pollution from domestic use would drop considerably. At a rough estimate, gardens in the UK occupy about 4500 km2 of land area (Davies
et al. 2009), mostly in urban and suburban areas. This makes them a precious resource and opportunity for change on a big scale.
The first thing we have to do is start looking at our environment as a living bio-system; in this case, the house and garden, with its connections to the wider world (air, earth, wind, rain, food, materials, waste, energy, communications). Think of the garden as one cell in a big organism. Almost all the elements this cell needs to survive are coming from outside, beyond its sphere of influence. Yet the way that cell is constructed, used and connected to its immediate surrounds (garden) could, if designed correctly, reduce its dependency on external manmade systems. To decrease those we must increase our connectivity with natural systems, namely the sun, wind and rain. To put it more directly, with have to reduce to a minimum the inputs and outputs of our homes.
A fedge (fence-hedge) uses biomass grown in the garden to create new boundaries. Good for wildlife and resource conservation.
Those items which we cannot produce internally need to be sourced from outside as close to us as possible. Therefore neighbourhood and regional systems need strengthening to minimise production/transport costs. This is particularly true and desirable for food products, but also building materials etc. For that reason, even if we manage to live off-grid – the ultimate, but extreme, conclusion to this line of thought – we cannot do it all alone and live in splendid isolation, nor would most of us want to. Many bio-systems will only work efficiently when connected together to give sufficient inputs to allow them to function properly (for example, reed-bed sewerage systems). Local community-generated bio-systems are essential to a sustainable future.
The main areas which the outside garden spaces could deal with are:
Passive solar gain (microclimates)
Water saving and (grey water) cleansing
Waste recycling (composting)
Increasing site biomass
You may think this all sounds very philanthropic, but where is the incentive to expend all this time and money “greening up” our homes and gardens? Some of the incentive will be economic; for example metered water users already consume about 15% less water than unmetered and government will gradually introduce a number of Carrot and Stick measures. But as cost of pollution will have to be met by industry and so, by consumers, simple economics means that inevitably everything will get more expensive. For many people, I suspect that having a lifestyle that gives independence and doesn’t add to pollution will become increasingly desirable, as we all witness first or second-hand the effects of climate change. Whilst we all see the horrors of hurricanes and droughts in distant lands, at home (for me, the UK) we see increasingly severe flooding etc. right on our own doorstep. Less dependency on outside systems will give increased sense of security in an uncertain world.
In all of this, beauty and relaxation will be paramount, so gardens will still fulfil this most traditional and personal of roles, giving us joy, relaxation and sanctuary. For example, looking at a beautiful water system of rills and planted gravel filterbeds is made all the more exciting by knowing it has a useful function and is saving resources.
A rain garden which captures roof-water and allows it to infiltrate the ground
For these principles to be taken up by the average garden-owner and made successful, we must resolve two conflicting issues: the subject needs to be driven by a sense of fun, adventure and positive aspiration to really make a difference and yet we must also avoid the “dumbing-down” or over-simplification of a complex topic, something that can occur when it appears in magazines and TV shows.
An example might be solar panels: it would be wonderful to run your garden pond pump, shed, or garden office from solar panels – no cables to the house to bury, a good eco-friendly solution. But you have to balance that ideal with the cost of initial installation (probably greater than laying electric cables from the house), the limitations of supply and the increased maintenance that may be involved. Having got your solar supply, you might be frustrated to find that you can’t charge your battery mower if you didn’t purchase a high enough generative capability. This is typical of a fragmented approach to sustainability – it’s a start but not really useful just thinking of the power to your pond and ignoring that used within the house, or your car.
So where are we? Standing on the threshold of an exciting new future, I would say. Technology and information is available as never before, and hooking up to the IoT (internet of things) is great fun and useful too. The brightness, however, is troubled by the looming stormclouds on the horizon and the knowledge that the societal cost of failure is high – and will be witnessed by ourselves but paid for by our children.
I do firmly believe that we can all make effective choices in what we do and in what we demand of the world, of business and our societies. We have to make rational choices and sometimes temper our own personal indulgence. Gas or electric patio heaters may be a nice luxury but the environmental damage is not justifiable. Maybe a log burning fire basket is, provided we do other things to counter the carbon emissions, such as growing more bio-mass. Extra woolly jumpers may simply be the best bet along with passive solar designed spaces! Most issues simply come down to us making informed decisions and balancing personal ease with environmental sanity.
Remember, what sounds “eco” or fringe today, is going to be tomorrow’s norm. Get out there, explore ideas and enjoy being the change!