User blog comment:Milesprower2/Spikerocks are defensive!/@comment-5792287-20121130103422

But they CAN block Zombies, and are very useful in Survival: Endless as a result.

Just because they can only block Gargantuars and Giga-Gargantuars doesn't mean they don't count, after all, no other plant can block Gargs and Gigas.