Climate Adaptive Gardening

INTRODUCTION

To start, we should consider what climate change actually is and how likely it is to affect our gardens, landscapes and plants, as well as how we grow them. Climate change is not new; it has been gradually building up over the last century. It is now at the point where it is causing problems and we have enough knowledge to know that things are only going to get worse in the future unless we do something about it.

WHAT IS CLIMATE CHANGE?

Climate change is a very gradual change in our climate over many years, resulting in alterations to the weather patterns in various parts of the world. Although, at first, the changes do not look too untoward, many of them are detrimental to our way of living and are causing environmental problems such as drought, flooding, storms and heavy rainfall. These are problems that have occurred in recent years and are predicted to get worse in the future, leaving a generation with many large-scale issues to solve, including possible mass extinction of some species, increased damage to property and the environment, and larger weather extremes.

The effects of climate change are caused by the gradual rise in global temperature caused by increasing levels of carbon dioxide (CO2) and other greenhouse gases, such as methane and nitrous oxide, in the atmosphere. These gases accumulate in the upper atmosphere and trap heat from the sun within the earth's atmosphere, slowly raising the temperature. At the time of writing, the world is approximately 1.2°C warmer than pre-industrial levels of the nineteenth century. In that time the CO2 levels have risen by approximately 50 per cent to nearly 400ppm.

These changes have been caused by mankind and most of them have happened in the last fifty years owing to the use of fossil fuels to provide energy for electricity, heating, manufacturing and transport. To prevent the worse consequences of climate change occurring, we need to limit the rise in global temperatures to 1.5°C by the end of this century. As things are at present, the temperature is predicted to rise to 2.4°C by 2100 - some scientists are even predicting a rise of at least 4°C, which would have massive consequences to the planet, its environment and its plants and animals.

The weather of the early 2000s and recent catastrophes will just be a forewarning of what is likely to come by the end of the century. Taking 2021 as an example, there was extensive flooding in parts of Europe and China, storms in the tropics (even in the UK), hurricanes and typhoons in the USA, as well as large wildfires in Australia, Greece, Canada and the US. Some farmland is turning into desert owing to droughts, heatwaves and soil erosion caused by poor or no soil care.

HOW CAN WE SLOW DOWN OR STOP CLIMATE CHANGE?

To try to prevent climate change from happening we all need to take some action, and the aim of this book is to offer guidance on what can be done in the garden to adapt to these changes and still grow good-quality plants and food. One single thing or person is not going to solve climate change - it will need many actions by many people - but we can all do our bit and make a difference. Many small actions, such as living a more sustainable life, growing more of your food, reducing your carbon footprint and encouraging others to do the same, will make a difference over time.

It is up to the politicians to lead and set strategies and targets, and we need to do what we can to meet these targets. It will take a bit of effort and we will need to change our lifestyles a little but the alternative for future generations does not bear thinking about. We owe it to them to leave a planet that is in a condition suitable for living on.

If a few people plant a tree it will make little difference, but if everyone in the UK (approximately 66 million at the last count) plants a tree, this starts to make a bigger difference. Over time, they will sequester carbon from the atmosphere, reduce pollution, provide shade and reduce windspeed. Sequestering carbon into trees will not solve climate change on its own, but it will help, and tree planting should be encouraged. There are trees suitable for every garden (even small ones), it is just a case of choosing the right plant for the right place. We can all do more than plant a tree, as I hope this book will show.

If we all do nothing, or very little, the likely effects on the UK will be wetter winters with heavier rainfall leading to flooding, soil erosion and waterlogged soil, which all affect plant growth. The amount of flooding has increased greatly over the last five years and will continue to get worse. Waterlogged soils can kill plants or at best restrict and stunt growth, resulting in poor flowering and fewer crops. Regular waterlogging considerably restricts the range of plants that can be grown and very few are plants that will produce a crop.

During the summer more droughts are predicted, again leading to poorer growth and lower yields as well as restricting the range of plant species that will grow and thrive. There are likely to be more storms causing damage to plants, especially if they are in full leaf. Damaged plants are more susceptible to be attacked by diseases, making plant care more difficult. Storms also result in damage to greenhouses, polytunnels, sheds and other garden buildings, as well as serious soil erosion if windy, and dry soil also reduces soil fertility. Although not predicted to be frequent, heatwaves cause damage to many plants, which tend to shut down when temperatures reach 30°C as this seriously affects enzyme processes within them.

To slow down and eventually stop climate change, many countries agreed at COP26 to be net zero CO2 producers by 2050. According to climate scientists this is achievable, although progress has been very slow so far. To achieve this target will require everyone to make changes to their lifestyle and needs leadership from governments, organisations, companies and individuals. As individuals we can make a number of changes, some of which are covered later in this book, but non-gardening ones include flying less, making fewer car journeys, using electric- or hydrogen-powered cars, reducing energy use in homes, increasing renewable energy and generally moving towards a more sustainable lifestyle.

We cannot continue with 'business as usual' and hope to thrive or even survive in the future. We need to adapt now to reduce our use of carbon and the amount of carbon dioxide, nitrous oxide and methane we are producing, which are key factors in the cause of climate change. We need to start living more sustainable lives now and make further changes into the future to take better care of the environment and develop more biodiversity.

If we are to live on this planet long term, we need to learn how to make changes and actually make them; we need to truly address the issue of climate change and not be overawed by or depressed by the situation. Action will make a difference. You can start in the garden and house by making small changes to reduce energy use, grow more food, recycle waste, compost green waste and more.

THE EFFECTS OF CLIMATE CHANGE ON THE GARDEN

Drought

The first effect of climate change on the garden is drought. This was driven home in the UK by the summer of 2022 - or for those that remember it, 1976! Although 2022 had some heavy showers, the overall amount of rain was well down on the normal UK average, resulting in long, dry periods, which were worsened by very hot weather in July and August. Many lawns went brown, young plants and bedding plants died (unless watered daily) and others failed to make the growth they usually did, giving smaller plants. Large numbers of vegetables failed to produce a crop, or if they did it was a much smaller crop than expected. It was dry for so long it was not possible to sow replacement crops unless irrigation was available.

Droughts are predicted to become more frequent and last longer. This will have an effect on the choice of plants that can be grown and yields of fruit and vegetables, which will affect food prices. Drought is not just caused by higher temperatures but also long periods without rain, lower total rainfall and increased winds, which both dry the soil by evaporation and increase plant transpiration as the wind or breeze draws moisture from the leaves.

Allium 'Globemaster'.

Fabiana imbricata.

Hosta 'Big Daddy'.

Wisteria floribunda 'Macrobotrys.

Higher Temperatures

Higher temperatures are also predicted as a result of climate change. These were also witnessed in 2022 in the UK, with the highest temperature on record achieved in July and several days with very high temperatures.

High temperatures not only dry out the soil but they increase the plant transpiration rate, meaning the plants need more water, which often is not available. Some of the plants growing in the UK have not evolved or adapted to high sunlight and these can be sun scorched, resulting in dead patches on the leaves. In future, we need to choose plants that have adapted to the high levels of sunlight and temperatures - these will be plants from Mediterranean climates or even warmer areas of the world.

More Storms

Climate change has resulted in more storms, and these are of a greater severity than many in the past. Again, 2022 was a good example as the UK suffered storms Malik, Corrie, Dudley and Eunice; two of which were very severe in the south of England, causing a lot of damage to gardens.

If storms become more common, we will need to take action to reduce...