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 rain is rain consisting of water droplets that are unusually acidic because of atmospheric pollution-most notably the excessive amounts of sulfur and nitrogen released by cars and industrial processes.amage to forests by acid rain is seen all over the world, but the most advanced cases are in Eastern Europe. Itâs estimated that in Germany and Poland, half of the forests are damaged, while 30% in Switzerland have been affected.