Last Name, First Name, "Blog post title." [Weblog entry.] Blog Name. Sponsoring organization (if any). Date Posted. (URL) Date Accessed.
Last Name, First Name. (Date Posted) Blog Post Title. Weblog entry. Retrieved on Date Accessed from URL.
Last Name, First Name, "Blog Post Title," Blog Name, comment posted Date Posted URL (accessed Date Accessed).
There are variations, of course; unsurprisingly, since in philosophy no one actually cares about citation format as long as you're close enough to whichever standard (MLA, APA, Chicago, or other) is proposed that you are not obviously wrong.