The Zelkova Somebody Keeps Measuring

Somebody has put a tape around this trunk three times in forty years: 3.30 metres in 1980, 3.89 in 2001, 4.40 in 2021. Very few trees anywhere carry that kind of paper trail, and it means you can watch this one grow at roughly two and a half centimetres of girth a year without waiting around for it. The garden planted it in 1891 and credits it with the widest crown in the whole collection, which in a place this old is a real claim. Zelkova serrata comes from Japan, Korea and eastern China, where it is the keyaki, the timber used for temple pillars and the bodies of taiko drums, and it is the species most often trained as a broom-form bonsai because the branching is naturally so even. At full size the same habit produces a vase: a short trunk dividing into a fan of near-equal limbs. The bark is the detail to look for. It flakes off in small rounded plates and leaves orange patches underneath, so the trunk reads as a mosaic rather than a texture, and it is the fastest way to pick this tree out from the path. In autumn the leaves turn orange and rust before they drop.