Trilobites: Why Does Fall Foliage Turn So Red and Fiery? It Depends. Many of the hypotheses for why leaves turn red before they fall off trees in the autumn sound contradictory. Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:Ant Obstacle CourseCelebrex Is Found to Be No Riskier for Hearts Than Other Pain DrugsTonight’s the night for rare 'supermoon' to make a spectacular sightSinosphere: China’s ‘Saddest’ Polar Bear Will Get a Temporary Reprieve From Mall EnclosureScienceTake: How Teamwork Brings Home the Tuna in Lego LandWhat is the supermoon? The phenomenon explained