A box and whisker plot is a graphical method of displaying variation in a set of data. In most cases a histogram provides a sufficient display; however, a box and whisker plot can provide additional detail while allowing multiple sets of data to be displayed in the same graph. Some types are called box and whisker plots with outliers.
Can you compost Leylandii branches and hedge clippings - Yes. We were quite surprised to learn some experienced composters advise not to add Leyandii cuttings as they are apparently too acidic. Composting bacteria can remain active in all but the most acidic conditions.
You can start a compost pile any time of the year, but there are limitations during certain seasons. You can build your pile as materials become available. In the spring and early summer, high nitrogen materials are available, but very little carbon materials are available unless you stored leaves from the fall.