Simply open your wp-config.php file (located at the root of your WordPress install) and paste the following code:

define('EMPTY_TRASH_DAYS', 10 );

 

The second parameter is when to empty trash, in days.

If you’re like me, you’re constantly forgetting to permanently delete posts, comments, and pages that fill up your trash folder. If you don’t empty an overloaded WordPress trash bin your blog may experience slower loading times as a result. This fix will not only take care of a piece of routine blog maintenance you’re likely to forget, it should also help your site run faster.