Gardening for climate change
There are many things you can do to help your garden cope with climate change.
Climate change affects every gardener in the country. Life is a garden, and to those of us who are really passionate about our gardens and growing plants, it would seem that both us and our gardens are going to have to change in order for us to carry on doing what we love best. The South African country study on climate change has been analysing the possible effects of climate change on various sectors of South African society, including agriculture and water provision. The Climate Change Research Group at the SA National Biodiversity Institute has also been investigating the impacts of climate change on indigenous plants in South Africa. The forecast for the Western Cape includes a possible 25% loss of its current winter rainfall.
Research also indicates that rapidly changing climate patterns will cause the extinction of many plant species within the next 100 years. There is concern that many habitats will be radically altered by ‘migrating' species that will move in, causing the extinction of indigenous species that have no suitable alternative habitat in which to live. Invasive alien plants such as the triffid weed (Chromolaena odorata) will become even more widespread, just as hadeda birds have moved down to Cape Town from further north.
Although the fynbos biome may lose a large number of species, the extent of the biome as a whole could remain fairly constant as fynbos grows in mountainous areas and it can retreat to cooler altitudes. Fynbos near the coast, where the climate is milder, will experience less of a change. How awful, you might think. But challenges are good for us and we have been challenged before as a human race and overcome. Let's get on with ensuring that life is a garden and start with the few tips recommended below.
Tips for coping with climate change
- Group the plants in your garden according to their water needs. Keep water guzzlers to a minimum. Remember not all indigenous plants are water wise and, equally, not all exotics are waterholics.
- Avoid watering your garden when the wind is blowing. Water less frequently but deeper. Dig basins around trees to collect the water.
- Use an irrigation system; drip irrigation can save up to 60% of water used by sprinklers.
- Set your irrigation system to water during the cooler parts of the day and during the night.
- Set up a rainwater tank to collect the rain that falls on your roof – from a 400m² roof surface you can collect 4 000 litres of water when 10cm of rain falls.
- Redirect bath and shower water as well as any other grey water into the garden.
- Try to reduce evaporation in your garden by planting a hedge of shrubs or trees that will break the prevailing drying south east winds of summer.
- Remove the lower branches of trees and shrubs so they can give shade which helps reduce excessive evaporation.
- Construct pergolas and structures that can also provide shade for certain parts of the garden.
- Improve the condition of the soil – soil that has regular compost added to it is able to retain water better.
- Mulch plants well – it keeps the soil cool as well as moist.
- Make new plantings in autumn when the rains start. They will now have the entire winter and spring to settle in before the really dry weather begins.
Water smart plants
It is a good idea to concentrate on planting those plants that are adapted to coping with low rainfall areas, so when you are on the lookout for new plants keep an eye open for those that have the following attributes:
- Fleshy succulent leaves, such as the aloes and the vygies.
- Bulbs, such as the ixias, watsonias, freesias etc.
- An underground storage facility in their swollen roots, e.g. agapanthus.
- Have a summer dormancy cycle to avoid the heat of the hot season, e.g. sparaxis and March lilies.
- Those that have reduced leaves such as restios.
- Plants that have a tough stem and leaves that reduce wilting, such as proteas and leucadendrons.
- Silvery leaves that reflect the light away from the plants, such as helichrysums.
- Those that have hairy leaves to reduce water loss.
- Plants like ericas with tiny leaves.