The RHS has just published a report called “Gardening in a Changing Climate”, in which it brings together the latest scientific evidence and sets out the likely implications for gardeners.
Climate change is already happening, affecting weather patterns around the globe. 2016 was the hottest year on record – the second and third hottest were 2015 and 2014. 16 of the 17 hottest years on record occurred this century (the outlier being 1998, so basically only 1999 bucked the warming trend). Even if we stop emitting greenhouse gases now, temperatures will continue to rise for a while as there’s a lag in the climate system (in part due to the oceans warming more slowly than the atmosphere). And it’s obviously vital to reduce our emissions quickly and drastically if we are to keep the eventual temperature rise to the 2°C scientists consider safe.
In the south east, as well as getting warmer, there will be greater weather extremes, so we can expect droughts interspersed with heavier, stormier rainfall – a tricky combination to manage. The growing season will be longer, increasing the range of plants we can grow, but some of the plants we currently have may be ill equipped to cope with the new conditions, a particular problem for trees.
So what should we gardeners & allotment holders do? Here are the RHS recommendations:
1. Green your living space.
Trees and plants remove heat–trapping CO2 from the atmosphere, reduce the risk of flooding, and some species can even capture particulate pollution.
2. Plant a diverse range of plants in your garden.
Earlier flowering might disrupt host–pollinator associations, so plant a diverse variety of pollinator friendly plants with different flowering times.
3. Adopt new ways of growing.
Green roofs and walls can result in year–round home energy savings due to a cooling effect in summer and an insulating effect in winter. Improve energy efficiency through use of technologies and try to reduce the use of petrol–powered tools.
4. Water use and management in gardens.
Seek water butts with a larger than standard capacity to ensure a sufficient water supply over the summer. Select plants and design strategies better suited to the environment.
5. Avoid peat.
Peatlands store considerable amounts of carbon. Look, ask for and use peat–free composts. There are now some high quality products out there that work.
6. Compost your garden and kitchen waste.
Gardeners may wish to compost more garden and kitchen waste as this provides excellent nutrients for the garden, but thrown away as household waste, it ends up on landfill and produces potent greenhouse gases.
7. Adopt the 4R’s.
Reduce – the use of resources in your garden wherever possible, Reuse – household materials and seasonal items year on year, Recycle – your garden waste, plastic, glass and metals and Reinvest – help stimulate demand for recycled products by buying recycled items.
8. Avoid wherever possible the use of chemicals in your garden.
As a first choice, avoid the use of chemicals in the garden. If required, use products with a low carbon footprint.
9. Practice Integrated Pest Management (IPM).
Adopt a combination of good plant biosecurity, biological, cultural and chemical controls in order to minimise the spread of pests and diseases.
10. Invasive Species.
Gardeners should ensure that their cultivated plants remain in the garden, and that legislation is adhered to during plant disposal.
For more information, see the full report on the RHS website.