Question about automatically updating wordpress plugins

Is the server that is hosting my wordpress blog required to have an FTP server running in order to use the automatic update feature?

I recently moved this domain to a VPS with and one of the big things I want is ‘NO FTP SERVER’. I do all my transfers to and from the server using scp.

I refuse to add an ftp server for this one nice feature. Guess I need to find out if one is required, or if there are alternatives, or do I just have to upgrade my plugins the old fashion way.