Twisted Kingdom

I had to turn word verification on, I was browsing some older posts and I noticed that we had a major spamming problem! I have been deleting them as I see them. Is there a way to turn comments off to older posts without turning them off to newer, does anyone know? I get an email notification now, so I can catch it easily, but we didn't have it for a while, so there are probably lots of messes for me to clean up. If you are browsing older posts and see any spam, just comment if you would, and then it will be brought to my attention. Otherwise, I will spam clean when I have the time to.