All you have to do is create a new route in dlvr.it with Google+ as the destination and your RSS feed as the source. The tool will then watch your RSS feed for updates every 15 minutes and any new blog posts will automatically be posted to your Google+ Page.
You may publish multiple RSS feeds to your Google Plus Pages and #hashtags may also be added to your Google+ updates based on the category /tags of your posts. Similarly, you may define a custom schedule when updates should be pushed to your Google Plus.
While dlvr.it is the first third-party service that lets you cross-post content to Google Plus, they have made this feature available to paid users only and publishers will have to shell out $9.99 per month to populate Google+ with their RSS Feeds.
The other limitation is that dlvr.it can only push web content to Google+ Pages and not to your personal profile on Google Plus.
Also see: Generate RSS Feeds for Google Plus