Plants for a changing Mediterranean climate – managing and adapting plants and gardens in a changing climate.
As gardeners who work in climatic regimes that are generally termed ‘mediterranean’ we understand the broad parameters as being typified by short, cool and wet winters and long, dry, hot summers with brief and changeable intermediary periods which we understand as spring and autumn. Within these broad similarities we each experience differences at the extremes: some of us know winters with frosts and snow and some of us know summers with extended heatwaves; some of us garden in montaine regions while others make gardens in maritime zones all of which add depth and particularity to our sense of place. Thus has come about the long standing discussion between gardeners in south-eastern Australia, Western Australia, California, central Chile, Uruguay and parts of Argentina, the Cape Province of South Africa and the countries around the Mediterranean Sea about what constitutes the essence of the Mediterranean climate. Over time writers have attempted to establish a common understanding of the climate type by defining ‘boundary markers’ such as extent to which date palms or olive trees dominate the landscape of agriculture, or the extent to which cultures based around theMare Nostrum have occupied the region, or even the spread of religion and commerce. While many would consider the work of Fernand Braudel to be the apogee of exploration of the nature of the Mediterranean it would be remiss and limiting to not also consider the ideas put forward by thinkers such as Matvejevic, Magris, Ibn Battutah, Rackham or even commentators such as Tournefort, Dickens, Twain, Fulco, Origo, Newby, and Bogarde. Surely it is the richness and depth of all these shared experiences and insights that brings vivacity and life to our Mediterranean gardening.
In respect of Louisa Jones new book Mediterranean Landscape Design it is my belief that the easy facility she demonstrates in her writing is indicative of a deep and insightful understanding of her task of interpreting the interactions between the cultural, social and historical landscape of the Mediterranean expressed through garden making and landscape design. It is a book that substantially contributes to the construction of a global concept of gardening the Mediterranean way. Further to that construct must be added the work of Chip Sullivan, Jan Smithen and Nancy Gosling-Power in California; Jacqueline Tyrwhitt, Heidi Gildemeister and Hugo Latymer in southern Europe. We have yet to gain the benefits of the insights that will be offered by the publication of Gwen Fagans’s doctoral thesis on the garden history of the Cape Province, and we await with intense interest any similar publications relating similar themes in Chile, Argentina and Uruguay. We have much to look forward to with keenest anticipation; and perhaps my own few efforts to make a contribution to that body of research, observation and practice will also be found worthy of a place.
Pacific Coast Native Irises are very hardy but short lived perennials
that need frequent division to maintain special selected forms such as this hybrid
raised by Heidi Blyth in Australia. PCN's, as they are often known,
come freely from seed and show a wonderful diversity of flower colour and form.
Climate Change and the Mediterranean climate zones of the world.
I do not propose to make an extended statement here instead I simply refer to the extensive work done by French meteorological and climate scientists, and those of other countries around the Mediterranean Sea. Ample information is available on numerous websites which establishes that around the shores of the Mediterranean, as elsewhere around the globe, climate change is happening, that it is being caused by anthropogenic activities, that we are now faced with adapting to the changes that have been begun by those activities, that we will experience a warming, drying climate, and that the changes will bring about changes in the way we live and work. Similar reports are also available for other Mediterranean climate zones such as California, south-eastern Australia, and Cape Province; all have been made as a result of research commissioned by the Inter-governmental Panel on Climate Change through the initiatives of the United Nations organisation.
Summarising the several reports of the IPCC we find that the conclusions for each of the Mediterranean climatic zones are comparable, if not exact matches, in terms of projected outcomes: over the next 50 years air temperatures will raise between 3- 5º C, rainfall will decrease but severe flooding may increase in frequency, atmospheric humidity will decrease, the period of rainfall will contract, frosts will be fewer but may be more severe, seasonal wind flows will change and more severe gales may occur, ocean currents may decrease in intensity or may cease. All of these phenomenon will have impacts on the long-term weather patterns we experience, and inherently have the capacity to disrupt human activity in relation to health, mental health, community well-being, social organisation and security, food production and security of supply, water harvesting and distribution, and more broadly global trade, commerce, transport, travel, migration, communication, politics and international relations.
All this not-withstanding the human race have proven themselves to be an adaptable and resourceful collection of individuals who have the capacity to survive seemingly adverse circumstances, to develop new ways of organising and managing, to develop new technologies and to think creatively all of which should lead us to feel optimistic about finding effective solutions and taking collective actions to cope with the changes ahead.
Dietes x 'Highland Gem' has been bred and raised by me and is on trial
in several Australian gardens that experience Mediterranean-type climates.
It is diminutive alongside the species, flowering for many months. It
withstands mild frosts well and requires only average well-drained soil.
What can gardeners do to adapt to a changing climate?
While there are changes we will assimilate through organised governmental and systematic actions that will operate across entire nations, states, regions and communities, and there will be individual changes we engage with through the ways we work, travel, socialise, consume services and products, there will also be changes we can make as gardeners.
Collectively we can make changes through the plants and goods we purchase to make our gardens. In doing so we will bring about changes in the horticultural industry where-ever we live. We can change the ways in which we make our gardens and thus bring influence to bear on designers and creators, and on the support services that stand behind those people – landscape contractors, purveyors of furniture and fittings, irrigation installers, professional gardeners, arborists etc. We can also change the ways in which we use our gardens for recreation, entertainment and creating impressions. We can eschew gardens, and expectations of gardens that are no longer sustainable. We can change the ways we talk about gardens, and communicate with each other about them. We can move away from the concepts of fashion, exclusivity, novelty, ‘now-ness’ and everlasting change for change sake, and towards a course of action that is more closely researched and attuned to what needs to be done.
'Sustainability’ is term that finds expression here, yet it does not include creativity, diversity or excellence: it is a thing more mundane and altogether more prosaic. As gardeners and garden makers this is not a goal to which we should aspire. We can do much better than that I am sure.
We can do what gardeners have always done and achieve something greater.
We can look to tradition for inspiration and lasting connection, as Louisa Jones and many others have done. We can sense the enduring features of what we do as gardeners and build on them to make the future. Ours will not be an insensible grasping after novelty, sensation and modernity; it will be a sensible and sensitive response to circumstances. We will accept, rather than deny, the boundaries within which we have to do our creative work.
Unlike the fantastical and ultimately ephemeral Robert Irwin gardens of the Getty Museum and those of the tropical gardens in shopping malls in frozen Canada, Germany or Russia, we will concede to the changing climate the idea that humans are not in charge of everything and able to command, at whatever cost, a scheme totally out of alignment with the parameters of the natural world.
Nerine x 'Coconut Ice' is a winter rainfall bulb; one among many new hybrids
which are adaptable and colourful, excellent as a pot plant that can be flowered
on autumn in a sunny patio or cool greenhouse.
Individual actions we can undertake as Mediterranean gardeners.
- We can move towards the old Mediterranean horticultural and agricultural tradition which regards water as the most important resource we have; it is to be highly valued, carefully conserved, sparingly used and preferably harvested and recycled.
- We can utilise technological innovations to deliver water to where it is most efficiently applied in the exact quantities needed.
- We can plan our gardens to minimise the external impacts of exposure to wind and sun and maximise the live-ability of spaces outside the home. It is my view that the Roman model of urban villa housing, successfully adapted by some Arabic cultures, offers us much source material for retro-fitting established homes, and in designing new homes.
- We can plant more trees and tree-like shrubs to reduce the impacts of heat reflected from walls and to moderate the impact of heat sinks in urban areas. Our skills as horticulturalists will enable us to train and shape trees and shrubs to fulfil these roles.
- We can zone gardens for water use, planting accordingly areas of plants with high, medium, low and no water use.
- We can utilise a greater variety of hard surfaces and in some circumstances harvest the rain-water run-off in cisterns and tanks.
- We can engineer garden surfaces to direct rain-water into soakage areas where it can recharge below ground aquifers.
- We can move towards creating gardens that grow and flower during the rainy season and that rest during the season of no (or little) rain.
All these aspects of mediterranean gardening have been covered previously by authors and researchers.
Grass aloes are just being introduced and hybridised in
South Africa, New Zealand, California and Australia. With
large succulent roots resembling those of Hemerocallis
and deciduous growth they are remarkable, distinctive and
colourful. And they are hardy in moderate frost areas.
What new things can we, mediterranean gardeners, do?
- We must become much more discriminating and demanding consumers of nursery grown plants.
- We must educate ourselves and each other about plants well adapted to changing circumstances.
- We must create the demand for a new range of plants so that nurseries will be encouraged to risk changes in what they produce.
- This role has been successfully taken by the MGS and merits our continued support and active membership.
- We must look ahead as best we may and plan according to the expected climate changes, and with the changes we plan to make ourselves.
Calochortus leichtlinii is a hardy bulb from central California that should
be more widely grown. Given a sunny site and freely draining gritty soil
they prosper without any fuss and are best left undisturbed. Self-sown
seedlings will often appear around the parent bulb.
Survival & Adaptation mechanisms in plants
As we know that conditions will be warmer and drier we will be on the look-out for plants that have the physiological features that will enable them to survive and adapt. These are:
- Plants with mechanisms for storing water eg. bulbs, tubers and rhizomes.
- Plants with mechanisms retaining water eg. succulents.
- Plants with seasonal growth patterns that fit with the rainy and dry seasons we already experience in Mediterranean climate regions.
- Plants with structures which reflect heat – hard, shiny leaf surfaces, reduced leaf surfaces, waxy leaf surfaces, hairy leaf surfaces.Plants with reduced body surface areas eg. globular cacti.
- Plants whose seeds respond to events such as wild fires and bush-fires, drenching rains.
Many experienced Mediterranean gardeners feel they already follow these precepts and that their gardens reflect through their plant choices such guiding principles. However, a survey of the plants grown across the regions shows a great deal of similarity, a little regional specialisation and not a great deal of experimental diversity.
By this I mean that we use and know a communal palette of typical Mediterranean plants – oleander, rosemary, olives, cistus, santolina, artemisia, salvia, agapanthus, acacia, duranta, euphorbia, mesembryanthemum, agave, aloe etc – an eclectic global selection, if you will. In California and the SW USA we would find a greater selection of agaves and native trees such as ceanothus, eriogonum, arctostaphylos and grasses. In the Cape Province we would find more Aloe species and hybrids plus more native bulbs such as lachenalias, amaryllids, babianas, pelargonium species and succulents while in south-eastern Australia we would find more native shrubs like correas, prostanthera and climbers such as hardenbergia. This is only to be expected as the natural process of selection and introduction from native plant populations occurs. The transfer of good plants from the field of specialist collectors to the wider horticultural market-place through discerning selection is what has created the generous diversity from which we can make our gardens. The process itself is almost akin to osmosis; a slow permeation through a porous but resistant substance.
Faced with climate change it is our task as gardeners and nurserymen to speed up that process to ensure that our domestic and public landscapes and gardens can be maintained as green and welcoming havens from the distressed environment in which we will live. The reasons for this line of argument are twofold: one is to have available a selection of plants adapted to the new warmer and drier conditions; the second is to ensure the well-being of our communities particularly in relation to issues of health and mental health. The stress of coping with living in a changing climate will surely be more significant than any researchers have yet been able to firmly establish.
To support the development of such necessary resilience gardeners as individuals can take a simple and practical course of action by growing plants from seed.
Amarygia x multiflora is a 19thC Australian hybrid of Amaryllis and Brunsvigia.
It is prolific, flowers reliably every year, is drought hardy and asks only a sunny site.
Protection from severe and extended frosts is necessary.
What criteria should be applied?
- Seek seeds from plants which grow in regions warmer and drier than that where you live.
- Try more succulents and other xerophytic and geophytic plants that may prove themselves survivors in the changing circumstances.
- Look outside the usual sources, so if you garden in southern France source seeds from Australia, Cape Province or Chile rather than Morocco, Algeria or the Canary Islands – but maybe give some thought to those from Turkey, Israel or the Lebanon.
- Look for seeds of plants that will suit the scale of your garden eg. fewer trees and big shrubs, some shrubs, more bulbs and perennials, some climbers perhaps.
- Thorough research via monographs and websites.
- Take a few risks.
- Enjoy being a plant-hunter and explorer.
- Always avoid plants with weed potential.
References:
Bogarde. Dirke 1997 The Complete Autobiography, Octopus, London. Braudel, Fernand 1966 The Mediterranean and the Mediterranean World in the Age of Philip II, Harper & Rowe, New York.
Dickens, Charles 1846 Pictures from Italy, London. Gildemeister, Heidi 1995 and later ed. Mediterranean Gardening – a water-wise approach, Editorial Moll, Palma de Mallorca, Spain.
Gosling-Power, Nancy 1995 The Gardens of California, Clarkson Potter, New York. Ibn Battutah (1304 – 1368) The Precious Gift for Lookers into the Marvels of Cities and Wonders of Travel.
Jones, Louisa 2012 Mediterranean Landscape Design, Thames & Hudson, London. Latimer, Hugo 1990 The Mediterranean Garden, Frances Lincoln, London.
Magris, Claudio 1997 Microcosms, Harvill Press, London. Matvejevic, Predrag 1999 Mediterranean: A Cultural Language, Trustees of the University of California, Berkeley.
Newby, Eric 1973 On the Shores of the Mediterranean, Harvill Press, London. Origo, Iris 1957 The Merchant of Prato, Jonathon Cape, London.
Rackham, Oliver and A.T. Grove 2001 The Nature of Mediterranean Europe - an ecological history, Yale University Press, New York. Smithen,
Jan & Lucinda Lewis 2002 Sun-drenched Gardens: the Mediterranean style, Harry M. Abrams, New York.
Sullivan, Chip 2002 Garden and Climate, McGraw Hill, New York.
Tournefort, Joseph Pitton de 1718, A Voyage into the Levant by the late King’s Order etc, (2 vols.) first English edition, D. Browne et al, London.
Twain, Mark 1997 Innocents Abroad or the New Pilgrims Progress: Being Some Account of the Steamship ‘Quaker City’s Pleasure Excursion to Europe and the Holy land, New American Library Classics, New York.
Tyrwhitt, Jacqueline 1998 Making a Garden on a Greek Hillside, Denise Harvey (Pub.), Limni, Evia, Greece.
della Verdura, Fulco Santostephano 1976 The Happy Summer Days, Weidenfeld & Nicholson, London.
