height widget sidebar

Hi, I searched a lot for a solution of the problem below, but I cannot find a solution. In the website (url: Hagmeijer.nl) we have a few widgets in the sidebar with text. Now a part of the text doesn’t occur, because there is no more space. Is there a possibility to make the widget longer (taller height) so that it will become possible to have all the text in the sidebar widget. Otherwise we have to work wit a “read more” solution and then we have the problem, that the text is too short for a whole page. Kind regards Hans Hagmeijer