If you work in the realm of landscapes, you cannot ignore the huge rise in
the use of artificial plants, “green” walls and especially, grass. It’s a
booming business and many companies are doing very well from it. But we should
also be hearing warning bells ringing about how damaging these things are, both
to the environment and to our individual well-being.
I’m concerned about this damage, mostly to our inner beings. I wonder if we have become unable to
comprehend that such things show our disconnection from the real. I’ve worked with plants all my life and
always my prime motive has been our connection to nature. Now I design, write, think, talk; always my
concern is for the environment and the well-being of the human spirit. This artificiality
in landscape betrays both these things.
It is not enough to say this, so I must justify it, even though the obligation should really be the other way around; people who purvey such things should have to prove that they don’t cause ill-effects. But such is the state of human consciousness that commercial profit always comes before anything else.
This is not an article about the merits of grass as such, nor what we might use as natural substitutes; that topic has been written about many times. This is about what we do to ourselves when we surround ourselves with fakery – and I don’t mean in politics, although there are parallels, doubtless.
We constantly sell ourselves short on what it is we actually need, as
individuals. This is me, an environmental designer, saying us humans should be
selfish, and demand more. But not more in material terms, in things. More in
Soul, in environmental harmony, in biophilic contact. More respect for the
awesomeness of Nature. How can we substitute the reality of Nature with
plastic, and tell ourselves it’s okay? This is self-deception on a massive scale,
and we need to be aware of it, and reject it.
Before going further on the psychological front, let’s talk about the
environment. Artificial plants are mostly made from plastic (although high end
plants may be silk). Plastic is a one-way route to pollution and there is no
difference between the plastic in a green or artificial grass and the plastic
that’s floating around in our oceans. It’s the same stuff and will end up in
landfill, being burnt or in the sea as microplastics, amongst its peers.
Artificial grass also is responsible for killing off the soil and its
ecosystem in areas that once were living. Even (real) lawns are of
environmental benefit, although other forms of landscape are preferable and
yield higher benefits. Yet a lawn is alive, absorbs rainwater, has a life
within of earthworms, larvae and micro-organisms, and stores a surprising
amount of carbon. Artificial lawns do the inverse of all that and are not even as
low maintenance as people think, requiring regular brushing and hosing. You must
replace it every few years, too, with rubber crumb underlay being especially problematic
to dispose of.
We buy into these products because we think we are being sold an easy life;
in fact, we are being sold a deception, that Nature can be imitated, bettered.
That you don’t have to get involved with it in any way, that the real thing
offers nothing better, that biophilia (your innate need and love of Nature) can
be mimicked. But your inner being is not deceived, just your outer one.
On the whole, we don’t realise just how disconnected we have become, in our modern
societies. Each generation has less contact with natural systems and ecologies
than the last, and each generation perceives its own experience of reality as
normal, how things are. If we could go
back 100 years, I think we’d all be astounded at the verdancy and variety of
life, of just how rich and varied Nature was.
Perhaps then we would wake up to the fact that we have forgotten our
roots and lost our way. Now, we surround ourselves with the artificial and
think that it is okay.
Landscape design doesn’t help in this respect, especially in the public
realm. Commercial space becomes
dominated by hard materials; plants, where they exist, are regimented and
ordered. Water features are devoid of
plants because they are messy, need skilled maintenance and the chemicals in
the water wouldn’t support their growth anyway.
How sad, what an opportunity missed, what absence of life in our urban landscape.
In all our striving, we should remember above all where we came from. A disconnected life allows not only the
artificial to be okay, it switches off our concern from the environmental and climate
crisis, as if we live in a bubble of man-made life, separate from the planet.
So for the sake of you own being, ditch the artificial. Embrace the messiness and verdancy of Nature,
get your hands dirty – the bacteria are good for your health and your
happiness. Let your children experience
this, teach them about that wild and somewhat frightening side of Nature, for
it needs our respect, and our love. And
if we love Nature, we might just find we can finally love ourselves.
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 what 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.
What’s needed is 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.
Concrete is a wonderfully versatile material, which has been in use since Roman times and with it we can build amazing structures that would otherwise be impossible. Unfortunately it also carries a huge environmental cost, caused mostly in the cement binding used. Whilst gravel extraction is also an issue, for that there are some alternatives such as recycled, crushed concrete.
The production of modern cement (OPC – ordinary portland cement) is a hugely polluting process and produces around 8% of the world’s carbon emissions – at least twice that of the aviation industry. Whilst the Romans used a volcanic dust called pozzolona as their binding agent, until the invention of OPC, we used lime, in various forms. Lime too has to be processed by heat and so is not without it’s environmental cost, but it uses less energy to produce than cement and lime concrete/mortar reabsorbs carbon over its lifetime (if exposed to the air), offsetting some of the initial pollution. Moreover, because it is softer, materials can be disassembled easily, for re-use.
In a landscape, there is ubiquitous use of concrete in a range of structures – walls, paving, sub-bases, ponds etc. some of which could be reduced or avoided altogether. Whilst landscaping will always use an insignificant amount of concrete compared to urban development and infrastructure, there are good reasons to minimise the volume of cement and other hard landscape materials used.
Some of these reasons are for obviously sustainable goals: reducing material/resource input and carbon and other wastes. Equally important in my view, is to increase the soft elements exposed in a garden – soils – and to increase the levels of planting and foliage biomass/diversity. This thinking is about the increase of biophilic benefits.
However, if sustainability is to be given top priority – as it must – then the use of cement has to be reduced as much as possible. This is quite a challenge to us all, as it is not always easy to find an alternative and I don’t suggest for one minute that it should never be used, but it should be reserved for essential structural use only. Even then there may be alternatives. Recycled concrete can make a suitable aggregate (or part of) and low cement alternatives such as CEM 1 reduce the energy and carbon emissions tally.
I have used – and continue to use – concrete in many of my own designs and so this challenge is personal – but then aren’t all sustainability issues.
Let’s look at the different areas of the garden where cement is used:
Many walls use cement, either in mortar or in concrete blocks as well as in cement renders. In this garden (left) we built retaining walls using hollow concrete block construction on concrete footings with cement render and mineral pigments for the final colouring, with concrete paving slabs as coping. As the site was on a chalk hillside, it may have been possible to construct this using rammed chalk or earth. Indeed, we had a surplus of chalk on the site from the house construction and it would have made perfect eco-sense to have used this to build the walls. The walls could have been rendered using lime based mix, and the coping could have been stone. As the chalk hillside is inherently quite stable, rammed chalk could possibly have been used for the footings too. However, there are so many unknowns, and so few UK examples that it is a risk to do this, especially on such structurally critical terracing. Long-term effects of damp creeping into the walls would have been my main concern.
The cost of rammed earth construction may have been cheaper than conventional construction , both in time to do and in material purchase, especially when the removal off site of subsoil is taken into account.
The picture at right shows rammed earth walls in a sustainable landscape I designed for Grand Designs Live, ExCel, 2006. Rammed earth walls are made by compacting subsoil inside timber or metal formwork. The soil must be kept dry so it needs some kind of footing and capping, here provided by cast copings made with recycled aggregates and partial cement substitute (CEM 2 furnace slag). The gravel to the main paving area is a recycled brick/concrete mix, laid through a geo-grid membrane made from recycled plastic. The aim here is to be as carbon neutral as possible. Planting aspired to be edible (you can eat daylily flowers).
Walling alternatives to concrete include:
Cement alternatives/recycled aggregates
Timber walling (railway sleepers etc)
Round pole walling (preferably coppiced hardwood)
Fences & crib-type embankment walls
Brick/stone with lime mortar (brick also has high energy input)
Dry Stone walling
Modern paving is often made from concrete and in some instances it is quite hard to find realistic substitutes. Stone paving is the obvious one but can be expensive. There are many cheaper stone imports available these days, such as Indian Sandstone, which are cost-effective but which carry a high transport and pollution price tag. Reclaimed York paving is highly desirable and of course, reused, so environment friendly but will cost 2-3 times that of cast concrete or Indian Sandstone. Brick is also traditional as paviors but as for walling, still carries a high energy/pollution cost in production, plus is expensive to lay.
For larger areas and drives, self-binding gravels may be one of the better answers, as these form a firm surface, once compacted, without the use of cement. Recycled or local gravels are also acceptable and can be held in place using recycled plastic grids/membranes.
Paving is one of those areas which highlights the question of just what is sustainable. Is it better to use imported sandstone with its high transport miles but relatively low energy production, or locally made concrete paving with cement and aggregate use, but low transport miles? In either case, the (financial) costs may be similar. There are also ethical and human welfare considerations for stone imported from third world countries, especially in terms of working conditions, health & safety and child labour.
Timber decking can be a viable alternative, especially on sites with changes of levels. Local timbers of the more durable softwoods (like Douglas fir or larch), green oak, Sweet chestnut or recycled tropical hardwoods. All new timbers should be FSC (Forest Stewardship Council) certified. New hardwoods should be avoided even if the have an FSC certificate as there is much illegal timber that still gets sold and even managed plantations may still involves some environmental degradation. They certainly have high transport emissions.
Possible paving alternatives:
Recycled stone, brick, cobbles – and concrete slabs
Self binding aggregates don’t need cement
Fired paviors and tile look beautiful, but are still energy intensive
local or recycled aggregates and gravels
Decking can be used where appropriate
Locally produced concrete slabs minimise transport and can have lower carbon footprint than imported stone
Third-world stone may be low energy, but high transport emissions
Even natural looking ponds may use concrete in their construction and formal ponds may be dominated by it. Again choice of alternatives is limited.
Concrete is often used to retain rocks and place protective pads over liners, etc. In many places it may be possible to do without concrete pads, which are often used in a “belt-and-braces” approach to protecting a liner. Felt geomembranes are used as standard as a layer underneath and often inside the liner (this may in fact be degraded by contact with concrete) and in many cases, use of additional layers of felt may eliminate the need for concrete. Felt is usually a synthetic, petroleum based product, so also has its environmental considerations (as do liners!). I have successfully used old carpet as replacement for felt, under the pond (I wouldn’t recommend it inside) but be VERY wary of tacks that may have been used. Non-synthetic carpet will degrade over time, which must be born in mind. Of course, before the advent of felt, liners were simply bedded on a layer of sand.
Where rocks and stones create waterfalls, they are used to form spillways and to prevent stones moving when climbed over or stepped upon (an important safety consideration). It may be possible to use hydraulic lime based concretes for this, although I haven’t tried this out. Perhaps well laid rocks, without the use of cement are the key, which would require a careful re-thinking of the construction method. Nature doesn’t use concrete, but then natural streams don’t retain water within an artificial environment (liner). A more holistic approach to water features, where the roof water and household grey water are recycled and the pond design doesn’t hold a fixed level or amount of water, may be the long term answer.
So looking at alternatives to cement raise as many questions as answers and in the 12 or so years since this article was first written, there has been some progress, but not much. Best advice is to minimise the use wherever possible, recognising the long-term durability and benefits of strength that concrete possesses.
Rain gardens are a relatively new approach on how to deal with water in the environment. In the last 10-15 years, there has been a big rise in the use of SUDS (sustainable urban drainage systems), the practice of delaying the entry of rainwater into the drainage system by the use of swales, ditches and ponds. However, this is generally the domain of engineers who are mostly concerned with their pipework; rain gardens, on the other hand, do the same thing, but are equally concerned with aesthetics and ecology – and so are far more exciting. Easily applied to the domestic situation, but the concept works just as well in urban and commercial design. In fact, WSUD – Water Sensative Urban Design – looks set to take on this wider role in the municipal environment, possibly replacing SUDS.
Having built many water gardens in my life, I decided (in 2010) it was time to build a rain garden in my own home, where I could enjoy it and also monitor its performance. These pictures show the just-completed garden, only a few months old; it also rained right on cue and appeared to be working well!
So what is the “philosophy” of a rain garden: why build one? Well, flood prevention is one answer; if you have ever experienced floods in your area, you have directly or indirectly contributed to them. If the rain didn’t fall on your actual roof, it fell on part of the urban fabric that has been built to support you. Another answer is to re-charge ground water supplies; many urban areas have groundwater levels that are dropping due to the fact that rain cannot permeate the land where it falls (95% of urban land is impermeable). Water tables are also dropping because we are abstracting water far more quickly than it is being replenished.
Rain gardens are a great way to re-connect with nature, opening you up to the experience of natural rhythms and process. It will sit there quietly in hot weather, dry, yet still a micro climate for flora and fauna that like a little extra moisture, in the lowest parts, providing free drainage to the drier areas. When it rains, though, the garden comes to life; water from the roof of your house, instead of disappearing down the drain, starts running into the areas of dips and dry ponds you have created, perhaps having topped up your rainwater butts first. Gradually pools start appearing and maybe in a heavy downpour, water starts running between them. How long it then takes to dissipate will depend upon your soil type; I’m on an alluvial soil, so it is very free draining; on heavy clay it might take days for the water to disperse, and this might mostly be from evaporation. This is good too as it helps re-charge the local hydrological cycle, which is also severly lacking sufficient moisture content, and may well be a significant but overlooked driver of climate change. If you have limited space or can’t allow water to rise beyond a certain level (after all, you don’t want to move the flood potential from somewhere further away, to your own home!), then you might need an overflow which puts any surplus water back to drain, or perhaps (and preferably) to another part of the garden. You will have still considerably delayed the timing of water going to drain, as well as the volume.
In my garden, I have disconnected one of the main roof downpipes (which it turned out was blocked) and used an old steel channel I found when they demolished the adjacent dairy. We have old cast-iron downpipes so I bought a 90° bend and fitted that to direct the water into the chute. I then dug a channel and partly lined the bottom with plastic, because our ground is very free draining and I wanted to connect this to an existing small water feature, so that this was topped up by rainfall. Surplus water is then dispersed to the sides, through the planting. If I were designing this from scratch, I would put the pond before the raingarden, so this was topped up first. Having said that, this section of the garden has always been incredibly dry and I’m hoping that the ground will, over time, recharge itself and things will grow better. This dryness is evidenced by the fact that we have a young fig growing well, right by the downpipe.
In periods of heavy and prolonged downpours, it may be that the pond will overflow; this will happen at the back and will disperse out away from the house under the bushes. With our soil, I don’t see the need for any further overflow drainage.
The roof section that feeds this downpipe is about 50m2, south facing. We get on average 50cm rain per year, so this should capture 25m3/year. This morning in light/medium rainfall, the chute was delivering 3 litres/minute (nowhere near the rate of a hosepipe). The rain garden is about four metres long and I’m not sure how to measure the drainage rate of soil, apart from having the plasticity index measured in a lab but over time I will use these figures to try and calculate how much water is passing through the system; in theory 25m3/year.
I was sent this picture (right) of a rain garden I designed for a client around the same time that I made mine. What a great picture, it gets right to the heart for so many issues about life, play, learning, experience, the elements. We tend to over-design our environments for safety, yet end up sanitizing them to the point where life becomes uneventful and we loose the richness and diversity that being connected to nature gives us. On a rainy day most kids are sat in front of the TV; I think this as a much better option…
The soil in this raingarden is a heavy clay and so holds the water for longer. It is bigger than mine and would need to be to increase the percolation area. You can also see that mine is more planted and this is again a condition of its function – theirs was designed to be a play space for the children (which is why I’m so pleased that it is successful). When they have grown up, it can be planted more intensely. It also created a feature in an otherwise rather awkward, narrow, North-facing space.
Rainwater management isn’t just for large commercial or public-realm sites, it can be done in your own garden too, with multiple benefits to environment, garden, wildlife and of course, you.
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!
NOTE: This article was first written in 2006, so some aspects have been updated to reflect current realities.
Biomembranes is a term I’m borrowing from biology (the structure bounding a cell) to describe the outer skin of future self-sustaining buildings. I have stated elsewhere that I believe that for the built environment – and therefore our societies – to become sustainable, every building and community must deal with its own wastes, generate its own energy and provide nourishment – both physical and emotional – for the occupiers. Only by the creation of truly independant, carbon neutral buildings can we achieve this.
This would be a subtle and far reaching art, not easy to achieve but I believe that the rewards would be many, not to mention necessary. In this respect, the science of biomimicry will play an important part, for example, in developing paint-on polymers that photosynthesize energy, or tensioned fabric five times stronger than steel or kelvar, made with no heat or pollution, just like a spider’s thread. Whilst we haven’t perfected those products yet, let me list some of the benefits we can look to achieve in the near future:
horizontal and vertical skins of living plants that insulate, filter the air of dust and pollution, dampen noise and attract wildlife. Current living walls are used sparingly as art pieces.
composting and filtration systems that clean the building’s waste and return nutrients and water to the biomembrane and surrounding landscape.
Algal biofuel production using building wastes.
interior landscapes that provide internal cleansing and beauty.
blurring of internal/external space.
energy generation as integral with the building fabric as passive solar/pv/wind.
pedestrianised streets as wooded valleys or urban forest gardens.
SUDS drainage to filter excess water straight back to the local water table.
pedestrian/bike/electric vehicle shared surfaces removing car domination.
increase of social space by good design.
Some of these ideas are becoming well established, such as green (or living) roofs and walls, others are being played with by a few, but as yet, no one is trying to pull all these things together into a cohesive whole system. I am thinking of concepts such as combining vertical greening with greywater filtration, active cooling systems, air purification and algal biofuel from building wastes. I have recently been inspired by the work of the world-renowned architect Ken Yeang (Llewelyn Davies Yeang) based in London and Malaysia. Ken has worked extensively on the concepts of bio-climatic buildings and so his ideas are very close to my heart. Furthermore, one of his main concerns is the organisation of internal space by social structure, rather than by economic return on investment. This very much reminds me of the work of Christopher Alexander (see Pattern Language); despite apparent differences of style, the underlying philosophy is similar, Ken’s work placing it into a modern urban context.
There is a lot to do but the future will need autonomous
bio-buildings that take care of themselves without external input, other
than sunlight and human organisation. The main challenge is then to
retrofit these systems to existing buildings, which will always be the
large majority of available building stock.
Meanwhile, take inspiration from the work of Hundertwasser (top right) and Ken Yeang (bottom right). The application of green technology, biological water filtration and the use of every surface to create living, breathing buildings shows that humanity can and will grow up and see beyond the profit line, which so dominates and limits current thinking.
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!
A problem, or an opportunity for a new landscape paradigm?
I was recently working on a tree project in Abu Dhabi when I came across a derelict site which intrigued me with it’s range of exotic self-seeded, non-native plants. The site was next to the Corniche and sandwiched between the Formal Park, my hotel and Capital Gardens. It struck me initially as the perfect basis of a xeriscape, as all the plants (mostly trees) were thriving without irrigation. On closer inspection and identification of the species involved, things got more complex and raised a lot of potentially conflicting thoughts and issues.
A natural Xeriscape
The site was clearly awaiting redevelopment and the plant invasion was opportunistic. Nothing that I could identify was native, yet all seemed happy there. When you see the list, you might understand why. Amongst the plastic and litter I identified:
Of those plants, the P. juliflora was the most robust and when you look at its reputation, that is of no surprise. It was of landscape scale, lush and greener than anything in the adjacent parks. It’s form, leaf, flowers and seeds are attractive from a landscape perspective. Yet this is undoubtedly the most controversial plant on this list – some would say alarming. A Native of arid zones in central and South America, this was, like so many others, introduced into the UAE in the 70’s as a forestry plant. Lauded as something of a super-crop tree, it is tenacious, vigorous, provides fuelwood and stock-feed in the form of abundant seeds. The latter, it turned out, were a problem in that they are spread by cattle and are extremely aggressive. Plants also regenerate rapidly from the roots when cut back and they reputedly produce biochemical inhibitors to suppress competition (allelopathy). With no natural competitors in the UAE and roots that can descend 50m in search of water, they out-compete native flora, even their cousin, Prosopis cineraria (ghaf tree).
Prosopis juliflora flowers
P. juliflora has a low, mounding habit, attractive from a landscape point of view.
Also on the site were a number of Banyan trees, Ficus benghalensis, which seemed to be growing happily. Another tough survivor, it should be borne in mind that the water table here is likely only a metre or so below ground, although it will have a high saline content.
Then there was Eucalyptus camaldulensis , another forestry/amenity introduction of the 70’s, also known and now generally avoided for its aggressive roots, yet here looking beautiful with its grey, lanceolate foliage. This was the tallest tree on site.
Eucalyptus camaldulensis , showing adult foliage
Of course, there was the ubiquitous Conocarpus lancifolius, widely planted still yet also recognised and a danger to any nearby drains, and on it’s way out in popular use. Except it does make such a good tall hedge, and it has a much nearer native origin, coming from Somalia, Djibouti and Yemen. I’m not sure that the UAE landscape industry is ready to ditch it just yet.
There was even a palm, Washingtonia robusta, self-seeded around the place. Much of it was to be found growing underneath the canopy of the P. juliflora, so that at least is not put off by any allelopathic biochemicals from the Prosopis.
I believe this legume is Sesbania sesban, more commonly seen with yellow flowers. Rose-ringed Parakeet
Inhabiting, or at least visiting the site, was a Rose-winged Parakeet. Another exotic invasive with beautiful form but aggressive tendencies; it seemed appropriate to the moment, somehow.
What does this mean for future landscapes and ecology?
From a conventional ecology point of view, these plants are all threats, and the threats probably outweigh their usefulness. So why am I even talking about this? Clearly, the move towards more naturalistic landscapes draws heavily on native species and would shun all of these species.
Except we have climate change.
Climate change is the elephant in the room, when it comes to ecology, in fact when it comes to sustainability generally and a livable planet overall. That we have already moved beyond vital tipping points is highly likely; that climate zones are moving away from the equator at a rate too fast for nature to adapt is a fact. Flora and even some fauna just can’t move regions that quickly. They will adapt, eventually; but those that are rare, specialist and struggle with change, will die. The tougher generalists will adapt and survive. Nature will build a new ecology to reflect the new reality, and it doesn’t mind if it takes a few thousand years to do so. Only we humans mind and so, if we are to survive, we must adapt our environments to fit the new reality. It is a sad fact that many cherished plants will eventually die out or move zones. In the UK, I dread losing our native oaks (I view these as our ghaf tree equivalent), yet we may get Mediterranean species to replace them, such as holm and cork oak.
If you are already positioned in the arid equatorial zones then you have precious few plants that will form your new ecologies and landscapes. Perhaps the plants I have described above will be UAE naturalized-natives in 100 years’ time and the ghaf and sidr may be gone, or diminished, or moved north. I hope not, but before we spend vast fortunes on eradication and control of non-natives, we should look to the future. These aggressive invaders may just form the landscape of our children; I know I’d rather live with a landscape, than none at all. If there is no landscape, there is no life. They may, in fact, be here to save us.
Once we grasp this fact, we can look at building new landscapes to suit our changing environments. I’ve written about this before and you can read the articles listed below. We must be vastly more holistic in our thinking in order to do this and broaden our horizons to understand the new future. Technology will help us to monitor, collect data and produce working strategies. Robotics and drones will help manage and control plant communities. Alongside that, we need a vastly better understanding of soils, microflora and fauna, for the bit of nature that we see is just, literally, the tip of the iceberg. The selection of tree and shrub species for adaptation is easy, we get this wrong when we don’t deal in whole context thinking eg. only thinking of forestry or ornamental benefits.
The challenge ahead is huge but in a weird way, exciting; it will challenge the human race to grow. There’s a whole new science to develop and we’d best get on with it.
According to Google, the site has been cleared some time in 2019: