Greater Knapweed - Centaurea scabies is big and showy, like a cross between a cornflower and a thistle, with whiskery petals in a whorl. It is a valuable nectar source for insects and a favourite flower of butterflies, including the Marbled White and Dark Green Fritillary. It also has therapeutic properties, and was once used in skin ointments to heal wounds and infections. Centaurea scabiosa is a truly outstanding wild flower which outshines many cultivated plants.
Prevention of wasps and yellow jackets. Slice a fresh cucumber into thin slices and arrange them in a single layer on an aluminum pie plate. The cucumber must be fresh – the pan must be aluminum. The cucumber reacts with the aluminum and gives off a chemical reaction/scent that is undetectable to humans but drives wasps and yellow-jackets away and makes them flee the area.