The Calderstones Sweet Chestnut

The age of this sweet chestnut comes from a division sum. The Liverpool Botanical Society measured its girth at 683 centimetres on a field walk in October 2015, then divided by 2.5 centimetres a year, the growth rate they use for a tree in good condition carrying a full crown, and arrived at 273 years. Add the decade since and the answer is somewhere near 280. That is a method rather than a measurement, which is why the band here runs from 230 to 330 years and why nobody should quote a planting date for it. The size is not in question. At close to seven metres round this is a large sweet chestnut by any standard, though a long way short of the British champions, which run from roughly nine to fourteen metres. The bark is the thing to look at: sweet chestnut ridges twist as the tree ages, and on this trunk they spiral right round. The society's own note on the day was short and admiring, a huge tree with characteristic spiralled bark and lots of fruit. It shares Calderstones Park with the Allerton Oak and with dozens of other exotic specimens, including a giant sequoia planted as recently as 1964. Only one source has ever written this tree up. If you know of another, or you know exactly where in the park it stands, tell us.