Q.What Is A Resistant Cultivar ‘snowy’?
What does this mean? What is ‘snowy’? Paper birches are susceptible to a number of insects, including the destructive bronze birch borers. If you live in an area where these insects are a problem, try planting a resistant cultivar such as ‘Snowy.’
Snowy would be the commercial name given to a variety (i.e., cultivar) of paper/white birch (Betula papyrifera) that was developed via selective breeding by someone. It would be resistant -not immune- to those insects mentioned in the article that you were reading.