There is a huge chestnut tree 50 yards from my study. Chestnut trees make a lot of mess – shedding their conkers, spiky shells and leaves that are tricky to compost – but on the other hand, we have the tree to thank for two great shows: the first lasts for a moment in the spring when flowers seem to march up its canopy like an army of fecund little warriors; the second lasts the winter because the mature and perfectly developed crown of the tree – when leafless and therefore visible – is a marvel to behold. It seems almost to be worshipping God, lifting its mighty twisting boughs to the heavens.