Please visit my site.
kulturely.com

I'm using Joomla 3 / K2 / Protostar

Why are the blog posts in the mid section of my site showing in 2 columns?

If the menu item which is defined as Home is of K2>Lateset Items...
Then the paramter of "Number of columns" in the "Advanced Options" is used to determine how many columns you want in the layout of this menu item.

Ah, found the solution finally!!!!

Despite I have integrated K2 into my site, I still have Joomla to control parts of my site such as the top navigation bar.

Solution was:
Menu -> Main Menu -> select the primary Menu Item -> Advanced Options -> change the # of "Columns for xxx"

Alrighty, thanks yall!