Bartik theme: How to extend text/content below blocks in sidebar 1 and 2
Edit your page.tpl.php
Cut and paste both the sidebar sections into the content section.
Content section starts with:     &lt;div id="content" class="column"&gt;&lt;div class="section"&gt;

I mean these parts:

&lt;?php if ($page['sidebar_first']): ?&gt;
    &lt;div id="sidebar-first" class="column sidebar"&gt;&lt;div class="section"&gt;
      &lt;?php print render($page['sidebar_first']); ?&gt;
    &lt;/div&gt;&lt;/div&gt; &lt;!-- /.section, /#sidebar-first --&gt;
  &lt;?php endif; ?&gt;

&lt;?php if ($page['sidebar_second']): ?&gt;
  &lt;div id="sidebar-second" class="column sidebar"&gt;&lt;div class="section"&gt;
    &lt;?php print render($page['sidebar_second']); ?&gt;
  &lt;/div&gt;&lt;/div&gt; &lt;!-- /.section, /#sidebar-second --&gt;
&lt;?php endif; ?&gt;


I think you will need some extra CSS to make it look nice.