Oak Apple Day Oak Apple Day Restoration Day, more commonly known as Oak Apple Day or Royal Oak Day, was an English public holiday, observed annually on 29 May, to commemorate the restoration of the English monarchy in May 1660. In some parts of the country the day is still celebrated. It has also been known as Shick Shack Day, or Oak and Nettle Day. In 1660, Parliament passed into law "An Act for a Perpetual Anniversary Thanksgiving on the Nine and Twentieth Day of May", declaring 29 May a public holiday "for keeping of a perpetual Anniversary, for a Day of Thanksgiving
Oak "Lymantria dispar", which can defoliate oak and other broadleaved tree species in North America. A considerable number of galls are found on oak leaves, buds, flowers, roots, etc. Examples are oak artichoke gall, oak marble gall, oak apple gall, knopper gall, and spangle gall. A number of species of fungus cause powdery mildew on oak species. In Europe the species "Erysiphe alphitoides" is the most common cause. A new and yet little understood disease of mature oaks, acute oak decline, has been reported in parts of the UK since 2009. Oak processionary moth ("Thaumetopoea processionea") has become a serious threat