cherry blossom in full bloom in Christ Church Gardens with black balloons caught in a branch2018

Blossom Watch With Iain Brooks

The woodland conservationist, Iain Brooks, is working with us in Nottingham on ‘When This Tree Blossoms’. He has been spending some time in Christ Church Gardens as we wait for the blossoms and doing some research for us about cherry trees, Spring and the impact of climate change on the seasons changing. Here are some of his thoughts…

The impact of the weather and seasons on trees has been recorded around the world for 100s of years. A saying which is often used and one I grew up with is; if the oak before the ash, we”ll only have a splash, if the ash before the oak, then we”ll surely have a soak. This saying has a special significance because generally both trees come into leaf around the same time. However the oak is determined more by temperature and the ash heavily influenced by daylight hours, early spring early oak. Historical data has the ash first around 30percent of the time but since early 1980s the oak has turned to leaf around 2 weeks earlier and the ash 7 to 8 days earlier. Which has meant in Surrey ash has been first 3 times in 40 years and in Northumberland 3 times in 28 years.

Cherry trees have been especially recorded, with records in Kyoto going back 1200 years. Because there are hundreds of subtly different forms of cherry (mainly due to grafting) some types blossom earlier than others. The peak bloom (hanami) is when 70 percent are in bloom. Cherry trees going into blossom are determined by temperature and in Japan this is 11 days earlier than 1820s and 5 days earlier than 1920s due to spring arriving earlier with climate change. The U.K.and U.S. are also approximately 5 days earlier since 1920s but this is accelerating.

In the U.K.the “London Japanese Conversation Group” holds an annual hanami event in Kensington and Regent parks each year (dates to be determined due to bloom but predicted mid march in 2020) which has generally become slightly earlier in recent years. (Iain Brooks)

Iain was the first of us to notice one of the blossoms in Christ Church Gardens fell down during Storm Jorge. Frank has recorded the latest video diary from the gardens showing the fallen tree here.

fallen cherry tree in christ church gardens, March 2020

Iain is trying to confirm which types of cherry blossom are in the gardens and why they are so much later blossoming than many of the other blossoms that have been in flower since late January, like this Hawthorn that Iain photographed on February 13th March 2020, by the canal in Nottingham’s marina.

Hawthorn in flower in February along the canal in Nottingham, 2020