For some reason, Google doesn't make it easy to automatically post content to Google+. You can't add the URL of a feed and import the posts from a blog. There's an exception: Blogger.
If you've integrated Blogger with Google+, you probably noticed a Google+ sharing box after publishing a post. It only required one click to share the post on Google+.
Now you can get even lazier: enable "Automatically share after posting" in Blogger's Google+ section and your posts will be shared automatically.
Google says that "automatic sharing to Google+ is enabled by default on all public blogs linked to Google+ pages or profiles. When you publish a blog post, a snippet of the post will automatically be shared publicly on your Google+ page or profile." That's probably true for new blogs, but it wasn't true for my blog: I had to manually enable "Automatically share after posting".
You can still enable "Prompt to share after posting" if you like to see the Google+ sharing box. Disable both options if you don't want to share your posts on Google+. Blogger also adds "share" links next to "edit", "view" and "delete" and you can use this feature to manually share posts on Google+.
Update: This feature is buggy. Here's what I got after publishing this post:
{ via Blogger Buzz }