MAY 9, 2021
By Paul Homewood
h/t Ian Magness
Jackanory comes from Kew Gardens today!
Potatoes and lettuce will have to be replaced in the UK by small, mustardy root vegetables and dandelion leaves as a warming climate means we cannot rely on traditional crops, Kew Gardens has said.
Horticulturalists and scientists at the gardens are working to see which food plants can be grown to resist increasing pests and diseases, sunnier summers and warmer, wetter winters.
Next week, a new TV show exploring the secrets of the gardens will launch on Channel 5, showing how gardeners and scientists worked together during lockdown.
Helena Dove, who runs the Kitchen Garden at the facility, grows crops selected by scientists to see how they fare in a British garden plot.
She said that potato blight, a disease which can wipe out the whole crop, is becoming more common because of a warmer climate in this country. At some point it may become unviable to grow them, she and other horticulturists and scientists at Kew believe.
“Traditional potatoes are becoming very hard to grow because of blight,” she said.
Two strange-looking, knobbly little roots are being trialed instead, as they fare better in a warm climate and are resistant to blight.
The gardener explained: “We have been trying to grow root vegetables that could be substituted in the future. One we grow is oculus tuberosa, and tropaeolum tuberosum – the former is a little lemony root, it does really well, we are breeding it in the UK to make it more suitable for our climate. We also have a mustardy root crop, and sweet potatoes are doing well as well. They could be a replacement. We won’t know for tens of years but we have to start somewhere.”
Many who tried to grow lettuces during last year’s heatwave will have noticed it was an uphill battle. These hot summers are becoming more common, so Ms Dove is working to find hardier alternatives to the salad crop.
She said: “Lettuces bolt when it gets hot so we may not be able to grow them in hot dry summers. We are growing tropical leaves, orache, tree spinach, they are traditionally grown for their grain but the leaves are edible so they sort of replace spinach. We are also growing dandelion which have really bitter but delicious leaves. They will keep growing through anything. We are trialling all this for salad in the kitchen garden.”
The idea that potatoes need a perfect climate is nonsensical. They are grown in a wide variety of climates around the world, hot and cold, dry and wet:
Harvest can certainly be adversely affected by the weather. Dry summers can stunt growth, but equally wet summers are not good news either, as farmers found to their cost in 2012.
However potato yields in the UK have been stable since 1990, following a period of rapid increase:
And UK summers are neither getting wetter nor drier:
As for lettuces, the dear lady seems to have totally lost the plot. Again, lettuces are grown in many countries with warmer climates than ours, including India and Spain. However, temperatures above 24C are not optimal:
Hotter countries, such as Spain, get around this by growing at cooler times of year, typically November to April.
According to the British Leafy Salads Association, the lettuce season runs from May to October, but planting can commence earlier if it is a warm spring. And the warmer the weather, the faster the leaf growth:
In other words, lettuce production is likely to benefit from a warmer climate, as planting can start earlier and finish later.
As for days over 24C, the summer of 2018 notwithstanding, they are still a rarity in England:
In reality, whether British climate changes or not, the change will be so slow that nobody will even notice, never mind the lettuces!