The traditional British garden is under threat from extreme heat, the Royal Horticultural Society has said, as it launches a survey to examine the damage from this week’s heatwave.
It is likely that in the future delicate flowers including roses and poppies will have to be swapped for plants such as salvias and dahlias, which are more resistant to heat.
Many will have noticed their pot plants and prized garden flowers withering and wilting in the record heat, which reached 40.3C (104.5F) in Lincolnshire on Tuesday. Due to the climate crisis, temperatures such as this are likely to happen more frequently.
This means people are going to have to start thinking about what and when to plant in their gardens, perhaps meaning the traditional British garden will no longer exist.
The RHS is asking its thousands of members, as well as any other interested gardener, to tell them how the heatwave affected their gardens. They are asked to note the plants damaged, their previous known condition and when they were planted and last mulched, in an effort to help the RHS advise on plants to grow in future years.
Heat damage usually does not set in until about a week after a hot weather event, so the horticultural charity is braced for a flood of calls next week. However, there are already reports of acers and hydrangeas suffering. The signs of heat damage include brown and crispy leaves, and plants can be saved with watering of the roots and shading if the issue is caught early enough. For many plants it will be too late, so the RHS says they should be composted and turned into mulch.
Leigh Hunt, principal RHS adviser, said: “The extreme weather conditions could be a catalyst for change in what we view as a traditional British garden. For many years, gardeners have dabbled with more sun-loving, drought-tolerant plants in their gardens but the summer of 2022 and the anticipated damage it will cause to some favourites could see a more permanent move towards plants that can cope with both extreme wet and dry.”
Not only that, but shortly after the heatwave, it is likely that we will experience a “false autumn”, with heavy rain and lower temperatures before it gets warmer again, confusing plants and causing damage.
This means that gardeners need to choose plants which can deal with both droughts and colder, wetter conditions.
Hunt said: “In the coming weeks we’re anticipating a false autumn – whereby heat-stressed plants lose their leaves early or turn red or brown.
“For those experiencing plant losses this year we wouldn’t recommend replacing like for like and instead choose plants that will cope with hotter conditions, and not need watering in this summer and withstand long wet conditions in winter. Examples include daylily Burning Daylight, eulalia Kleine Fontäne and geranium.”
Heat-loving plants are already enjoying boosted popularity in the UK after a run of hot summers and fears of damage to more delicate flowers.
These include cannas, salvias and dahlias. Salvias are particularly popular and the most-viewed plant profile on the RHS website.
Plants we may lose from the British garden include roses, which go over more quickly in the heat. Leafy salads tend to bolt and go to seed in hot weather, and flowers including field poppies and calendula also go to seed more quickly.
