Configure WordPress Trash Behavior
If you want to change the number of days, WordPress keeps posts and pages in trash, you can add the following line of code to your wp-config.php:
define('EMPTY_TRASH_DAYS', 14 ); // number of days is now 14
If you want to disable the trash, you can set the value to 0:
define('EMPTY_TRASH_DAYS', 0 );