We have a couple of walnut trees on the farm that we share (unwillingly) with the local squirrel population. The first picking is of green walnuts in the second week of Wimbledon when the nut itself is still soft and unformed. These green walnuts can be pickled or used to make walnut liqueur. The biggest harvest is when the walnuts have ripened. It’s frustrating to watch the squirrels pilfer the walnuts just before they ripen, but in a good year there’s plenty for all. The walnuts are ready to pick when the green cases start to split, revealing the brown walnut shell within. You can break the shells and use these creamy coloured walnuts fresh, but if they’re left to dry in a cool, airy place they develop that rich, walnut colour and flavour. It’s well worth the wait and they last all winter.