Century-old weather records give glimpse into climate change
At a time when the COP26 conference has focussed attention on the changing global climate, we take a look at the weather recorded closer to home
Even earlier than that, before the land was gifted to the RHS and it was known as the ‘Oakwood experimental garden’ there was a tradition of noting down the daily weather and today there is a full, scientific weather station.
As well as giving our scientists our own meteorological record, it is one taken with a gardener’s eye. So it includes the first frost of the autumn, when the roses first came into bloom or when the
An example of a weather record taken on 29 June 1890 at what was then known as the Oakwood experimental garden
“The last frost is much more random. In 2020, for instance it was mid-May.”
Predicting when the last frost of spring may bite is becoming increasingly hard with every passing year
The number of days where the temperature tops 30C is now much more frequent. We now see about a week a year compared with the beginning of the 20th Century when it was maybe two or three days a year.
The effect on gardens
Similarly, nights that don’t drop below 20C, those uncomfortable nights when it is difficult to sleep, are becoming more and more common.And what does this warming mean for gardeners? Perhaps most obvious is the
“Grass grows when it is warm enough so people start mowing in about March right up until maybe November.
“But summers are beginning to get so hot and dry it stops growing.
We need to change people’s ideas on aesthetics and get used to brown grass. Rather than watering the lawn, we leave it and don’t cut it between about June and September when the rains return.
That growing period, which has drastically extended over the past century or so, applies to every type of plant, each with its own unique requirements.
Some, such as fruit trees and bushes, require a chill factor. They need to spend some of the off-season cool enough to promote fruiting in the warmer months, and with warmer weather that does not always happen.
But there are other climate worries that vary according to geography and topography. Some parts of the country are facing frequent floods while others suffer prolonged periods of drought. Others still will be subject to both.
All of this horticultural knowledge and meteorological data, gathered using the latest scientific equipement, can be combined to continually improve the RHS’ research and therefore the advice it can offer to gardeners.
Where plants are comfortable growing is marching further north, so the RHS is working to plug the gap in the south with new plants.
But introducing new ones can be fraught with difficulties, pick the wrong species and it could have unintended and possibly devastating consequences.
