Category: green roof

Adaptive landscape design
April 25th, 2019 by Mark Laurence

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.

Posted in Adaptive Planting, Biophilia, Climate Change, Design, Ecosystem Services, Edible Planting, Environment, Garden Design, green roof, Green walls, Landscape Futurism, landscapes, living walls, Natural Landscapes, Planting Design, rain gardens, Regenerative Planting, Smart Cities, Sustainability, Trees, Urban Landscapes, Vertical Greening Tagged with: , , , , , , , , , ,

November 2nd, 2018 by Mark Laurence

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 system

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

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)
  • Energy production/conservation
  • Increasing site biomass
  • Food production
  • Biophilic nurturing
  • Nature conservation/biodiversity

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

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!

Posted in Adaptive Planting, Climate Change, Design, design principles, Ecosystem Services, Edible Planting, Environment, Garden Design, green roof, Landscape Futurism, Planting Design, rain gardens, Smart Cities, Sustainability Tagged with: , , , , , , , , , ,

June 28th, 2013 by Mark Laurence

Curiously, I’ve never really written about green roofs, yet they are an important part of the urban greening scene and definitely a part of my “building biomembrane” concept.  Perhaps it’s because the subject is so well covered by the commercial sector and various organisations; far better than green walls but then, they have a twenty year head start.

And twenty years ago, I was putting green roofs into some of the landscapes I designed and built.  Here’s one in my own garden, on a wood store:  the one at the back is an 18 year old turf roof, with soil and grasses, such as was common in those days.  There’s a lot of Sedums, Sempervivum, bulbs etc that have been added over the years, or found their own way there.  The roof to the front is about two weeks old, consisting mostly of Sedum album, which was growing prolifically in a graveled part of my garden where I didn’t want it.  I put a layer of soil and compost under it and slapped the darn stuff down!

green_roofs

I also have another Sedum/succulent roof over my porch, which is much more akin to a modern extensive green roof, with a mix of compost and expanded clay pellets (ie lightweight aggregate). It is much less prolific and to my mind, less successful therefore.  I used to be quite adept at building hobbit-like turf-roofed garden structures from chestnut and reclaimed timber, such as this one, built for a show:

Turf Hut 2

These days I like to do rustic with a contemporary feel, such as my current summerhouse, which I built last year. It doesn’t have a green roof, simply because it faces away from us so we’d never see it. It’s insulated and timber-lined inside, so stays fairly warm with a little help. The windows all came from a house up the road, so fitting my desire for recycling. Double-glazed too…

summerhouse

Of course, the best kind of green roofs are the ones you can use as garden or green space. I’m designing one right now which overlooks the Thames; an early concept modeled below. I’ll put more up on this as things progress…
MLD_roof_garden

Posted in Environment, green roof, landscapes, My Garden Tagged with: , , , ,