I’m building a wordpress site and am having trouble with the sidebar on my blog. I am currently using a child of the Twenty Thirteen theme with slightly modified CSS. The sidebar only has three widgets, so it does not stretch down to the bottom of the content area. I have tried to implement the Faux Columns solution, but have been unable to get it to work. (link: http://line25.com/articles/create-sidebars-of-equal-height-with-faux-columns).