During spring and early summer wasps are beneficial to our ecosystem, particularly for farmers and gardeners. They hunt caterpillars, aphids, houseflies, greenflies, grasshoppers and other insects to feed their young. It is usually only towards autumn when the workers no longer have to feed their young grubs that they look elsewhere to satisfy their craving for sweeter food sources by feeding on sugary drinks, jam sandwiches and cakes.
If you have a nest in the garden which is not close to your home and is not causing an immediate problem, you should try and leave it well alone. Once the cooler autumn weather arrives the worker wasps will eventually die and the queen wasp is unlikely to use the same nest next year.