The English hobby gardener William Tucker discovered powdery mildew for the first time in 1845 in Margate (county of Kent) in the southeast of England. He observed the white coating on the vine leaves under his microscope and correctly identified the fungus as the pathogen causing the disease. Tucker published his observations in 1847 in the "Gardeners Journal". Powdery mildew is also named after him as "Oidium tuckeri". The fungus, which was introduced from North America, spread rapidly throughout Europe before the phylloxera, which followed as a second catastrophe.