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 only one form of pollution that re-sults from burning fossil fuels. It is one of particular inter-est, however, because it can be transported over long dis-tances. Scientists, engineers, and researchers are learn-ing how to measure the amount and effects of pollution inthe air, forests, water, and soil.cid rain is only one form of pollution that re-sults from burning fossil fuels. It is one of particular inter-est, however, because it can be transported over long dis-tances. Scientists, engineers, and researchers are learn-ing how to measure the amount and effects of pollution inthe air, forests, water, and soil.