It is Saint Swithin’s Day today, 15th July: the day on which people traditionally watch the weather. Tradition says that whatever the weather is like on St. Swithin’s Day, it will continue the same for the next forty days.
There is a well-known weather-rhyme in Britain:
St. Swithin’s day if thou dost rain
For forty days it will remain
St. Swithin’s day if thou be fair
For forty days ’twill rain nae mair.
St. Swithin’s Day is also the ideal time of the year to prune walnut trees. Pruning walnut trees in the dormant season (i.e. when the leaves are absent) is not recommended as it is for nearly all other broadleaved tree species. If a walnut is pruned when the tree is dormant, or even worse when it is actively growing, the pruned wound will bleed profusely which will weaken growth the following season, and possibly increase risk of infection. Pruning is undertaken ideally near the end of the walnut’s active growing season and St. Swithin’s Day, in mid July, provides a perfect marker.