French hydrangea flowers for 5 to 9 weeks in late spring or early summer. The mophead or lacecap flowers develop from buds formed in the tips of stems the previous year (on old wood). Most older cultivars bloom just once.
Scientists discovered, and have confirmed, that sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain. In the US, About 2/3 of all SO2 and 1/4 of all NOx comes from electric power generation that relies on burning fossil fuels like coal.cid rain is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid deposition, which has two parts: wet and dry.
Acid deposition, also called acid rain, is rain or gases that have been polluted by high amounts of chemicals and acids in the atmosphere. It can result from decaying plants and animals or natural cataclysms, such as volcanoes, but the major cause of acid rain is the releasing of chemicals by humans.