So, for some strange reason, I was getting eleventy billion spam comments on one of my Halloween posts from last year. Spammers use some sort of keyword search to find posts that they think would be relevant to their spammy topic and somehow one of those desirable key words was in that post. I would get 10 - 15 spam comments a day on that post... it was obnoxious.
In an effort to avoid deleting spam comments constantly, and since the post was from last fall and probably wouldn't get any new comments anyway, I decided to shut off the comments for that one post. It was easy-schmeasy and here's how I did it (in Blogger, I've no idea about Wordpress):
Find the post you want to shut the comments off of and click the edit option. Once you're there, click on the "Options" tab in the right side of the screen, under "Post Settings".
Once you've clicked on that, you'll see that you can adjust the settings for the comments on that post.
As you can see, here's where you can choose to shut off the comments. You have the option to leave all the existing comments up (which is what I did) or to hide the existing comments.
This might not ever be necessary for your blog but if you ever find yourself deleting 15 spam comments from the same post DAY AFTER DAY AFTER DAY, you'll thank me.