If you can twig which tree is which you can impress people at an event in Pishiobury Park on Thursday (Feb 22). The Sawbridgeworth park is holding a tree detective event when people will be challenged to identify the 15 different types of tree and shrub there. Besides collecting evidence to help name the trees there will be simple, practical tasks for visitors to carry out that are suitable for families and friends. The meeting point is in the main car park off Harlow Road at 10am and visitors are advised that the park could be muddy and to wear appropriate footwear. Children are welcome but u…