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.
Depending on where you live, maybe you've heard of acid rain. Now, acid rain is not pure acid falling from the sky, but rather it is rainfall or atmospheric moisture that has been mixed with elements and gases that have caused the moisture to become more acidic than normal.Pure water has a pH of 7, and, generally, rainfall is somewhat on the acidic side (a bit less than 6).eographic distribution of acid rain. Acidity in rain is measured by collecting samples of rain and measuring its pH. To find the distribution of rain acidity, weather conditions are monitored and rain samples are collected at sites all over the country.