PurpleKudzu423, it's due to Rose. The Rose's tend to gather, at which point the other plants tend to gather around their Rose's. Which makes it hard to push them off of their turtled location. Each time you kill one or more of them, there's usually a few that survive due to Rose's ridiculous strength, which they then start reviving everyone to rob Zombies of kills, and they keep the zombie kills they scored.
Hopefully, after her nerf, it will make it easier to actually push them off of their spot. I expect it will though, as it seems the Zombies are better pvp'rs at this point. They've had to get better and better due to Rose, while most of the Plant's players just kind of sit around and hope Rose saves their arses.