Trees add height and microclimate
December 9th, 2019 by Mark Laurence

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.

Trees in grass lose most of their microclimate
Trees in grass lose most of their microclimate and ecology. Traditional design fails us here.

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…

Here we have (in Umm al Emarat park, Abu Dhabi) the beginings of an true microclimate. This is a treescape.
Here we have (in Umm al Emarat park, Abu Dhabi) the beginings of a true microclimate. This is a treescape.

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.

Are you up for it? I am!

Posted in Adaptive Planting, Arboriculture, Biophilia, Climate Change, Design, design principles, Dubai, UAE, Ecosystem Services, Environment, Garden Design, Landscape Futurism, landscapes, Middle-East, Planting Design, Sustainability, Trees, Treescapes, Urban Landscapes Tagged with: , , , , , , , , , , ,

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: , , , , , , , , , ,

July 10th, 2016 by Mark Laurence

This review first appeared in Thinking Gardens in February 2016.


This book represents a new wave of thinking about “natural” planting that has been emerging in recent years; actually it has been developing for the last thirty or more years but like all new things, they tend to follow an exponential growth curve. I’d say that right now we’re near the base of the steep upward bit with this one. Left unchecked, exponential growth tends to end in collapse but this idea deserves to stay the course. To do that it has to translate from a style into a design language and that’s what this book is really about.

This is a very US-centric book, unsurprising since Thomas Rainer is from Alabama and Claudia West, though of East German origin, lives in the US. I would have liked her influence to have given the book a more European feel; it would have been richer for it and more globally relevant.

The book has already been reviewed on TG by James Golden but although I’ve read this I’m not referring to it, save for one point. Needless to say, that review is also very US-centric; my purpose is to give a more UK/European viewpoint.

The thinking in this book is very design-led, in which the authors refer to landscape archetypes, which I think is very useful. However, they only select three – grasslands, wood and shrubland and forest. Given the vastness and variety of American climate types (which has just about everything), I’m surprised they didn’t mention desert landscapes, arid-mountainous or Mediterranean (as in Californian coastal regions); I suspect they have simply not worked with these climates, yet to omit them from a listing of archetypes is limiting. It is clear too, that their interest lies mostly in the grassland or prairie archetype.

Desert Archetype

There are many archetypes other than the three mentioned in this book. Desert near Dubai, UAE.

Referring back to the JG review, he wanted to add another archetype, Edges. I would argue that the wood and shrubland archetype is an edge, or rather a transition. Only in farmer’s fields do we have an edge as such. I would think of these archetypes as parts of a sine wave, one transitioning into another as climate and topography dictate. This sine wave also rolls around the globe over time, one archetype superseding another in any given place. Remember that the Sahara desert was woodland just 10,000 years ago, when we emerged from the last ice-age. This fits with the theory that there is no such thing as an ecological climax.

Another interesting thing to come out of this book is the idea of “designed plant communities”. You could say that any grouping of plants together is a designed community but the context they use of grouping plants by habitat-type rather than just their visual look is refreshing. This makes good sense, provided that such a designed grouping is appropriate within its wider environmental context. Taken to its logical extreme, however, you end up with native plants only.

What may be harder to work out is how much of this philosophy fits into a garden. Even the largest garden can’t fit in a whole wood, let alone a prairie, so of course, we must work by inference. This aspect of things is not really discussed in the book and most of the pictures are of large gardens in amazing settings; domains of the lucky few who we landscape designers occasionally get to work for. Yet for the majority of small garden owners, instruction for the adaptation of these principles is missing.

Millenium Park, chicago

The Lurie Garden, Millennium Park, Chicago by Piet Oudolf exemplifies modern Naturalistic planting. This is large ribbons or drifts of plants rather than the species intermingling favoured in this book

Millennium Park, Chichgo

The same garden in November; form is held in the stems and shapes of the seedheads but use of some woody plants might add more winter form?

I feel that the book only really looks at one archetype, that of New Perennial/Prairie style gardens and there is a big focus on this at the moment. I might compare this book with Oudolf & Kingsburys “Planting, a New Perspective”. That book, whilst not getting down to the archetypal design level, is more European in focus, so possibly a good companion read. Yet it too, mostly deals with perennial-based planting, as you would expect from these gents. The work of Nigel Dunnett and James Hitchmough comes to mind too. The fast-changing essence of many of the plant species used means that these perennial plantings are subject to rapid change, even degradation, over time as some of the most desirable and favourite species are so short-lived (Achillea and Echinacea for example).

I think the Wood and Shrubland archetype is the most likely to resonate with those seeking to create a garden, yet the ones of great importance to me, in a European and specifically coastal Southern England context, is that of the unmentioned Mediterranean or Arid-Mountainous archetypes. Whilst some areas of the Mediterranean clearly fit the Wood & Shrubland archetype (ie broadleaf and evergreen woodlands and Maquis), others such as Garigue, Salt Marshes and Rocky Shorelines, do not. I think this range and essence adds up to its own unique archetype. Arid-Mountainous too is quite distinct (although again with areas that fall into the realm of other archetypes), yet gives us wonderful, tough plants like Perovskia. The Dutch biologist Brian Kabbes has done much to inspire and educate us with his exploration of plants in Kyrgyzstan.

Perovskia arbrotanoides

Perovskia arbrotanoides growing wild in the mountains of Kyrgyzstan. Photo by Brian Kabbes

 

To me, one of the biggest drivers in creating naturalistic planting communities has always been about resilience. To my mind, planting should survive without irrigation, so low water-use plants are attractive. I can’t think of a single garden in the UK that couldn’t survive without irrigation, the desire to use pop-up sprinklers is ridiculous and surely industry-driven. Climate is changing now beyond speeds that Nature can shift plants and ecologies around the globe, so it is something we humans must do if we want a future landscape of any description (oh, and for our own survival). So we have to transmigrate landscapes from one continent to another to keep pace; yes, with all the risks that entails when introducing new species (and it would not be just plants we’d have to relocate). So learning about plant communities and how to build them is a vital skill which this book begins to explore, yet could have gone much further in instructing us on.

Mediterranean Archetype

This coastal garden I designed in Southern UK loosely mimics the Mediterranean archetype, and uses a full range of grasses, perennials, sub-shrubs, herbs, shrubs and trees.

 

In the European context then, archetypes other than grassland/prairie might be more useful and translatable into a garden context. That this book has not covered these is not really surprising but it is a mistake to think that the new language of resilient/natural/sustainable landscapes is dominated by perennials and grasses. This aspect is possibly a trend within the underlying drive for a natural interpretation.

A European version of this book is needed, which could perhaps take it to the next level of design language development. In this respect, inspiration can be drawn from another book, “A Pattern Language” by Christopher Alexander, which although about architecture and space, is also about soul, spirit, context and community, realised through the use of a language of patterns. In a very real way, “Planting in a Post-Wild World” attempts to create an archetype-based design language and is a valuable contribution to that. We just need the language to be global, or to see this book as a regionalised attempt to cross boundaries and develop new thinking.

This is an important book and I recommend it; for all its limitations it shows the way to develop landscapes that are truly new and profound.

Posted in Book Review, Design, Environment, landscapes, Natural Landscapes, Regenerative Planting Tagged with: , , , , , , , ,