Getting .htaccess to work for all directories

Question

I'm having a problem with .htaccess.

I've inserted

<IfModule mod_php5.c>
  php_flag include_path ".:/usr/local/lib/php:library/"
  php_admin_flag safe_mode on
</IfModule>

inside the public_html folder, and it works for that folder only. When I go into sub-directories of public_html, it ignores that and the 'include_path' is different to the one i specified.

I'm doing it this was because I don't have access to the php.ini file.

Anyone know where I'm going wrong? Thanks