I like the analogy between triffids and zombies. Both slow moving and not very bright.

The title "The Day of the Triffids" is a bit of a misnomer. The disaster is actually mass blindness, which would have been difficult to deal with even without feral plants.

I'm glad they mentioned "The Kraken Wakes". It's a shame they aren't making that one, as it would be more apposite if global warming is to be believed.