One of the problems with WordPress archives listed by month in the sidebar is that the list becomes really long when you have been blogging for a long time. Siel at green LA girl has been blogging since July 2005 and had removed her archive list from the front page sidebar because it had become so unwieldy.
I investigated a variety of solutions and Siel decided to use the Clean Archives Reloaded plugin, which creates a collapsible list or archived entries on an archive page rather than listing them in the sidebar.
Take a second to look at how the plugin works on Siel’s site and then come back and follow the installation instructions.
To install and set this plugin up on your site do the following: