Strategy needed:Wall nut/Boomerang is effective?

It's decent, but there are better combos out there. I'm going to edit this later with a picture of my current Wall-Knight deck build (my phone takes forever to email photos 😞 ) and describe some parts of it to give you some ideas for what works well with Wall-Knight. He's an awesome hero, and has strategies aplenty, so trust me when I say you'll have fun with him.

You can also check out this stellar site for deck-building tips: http://pvzheroesdecks.com/

It is pretty logical... you protect the strikethrough plants and they punch the zombie hero in return. It'd be a good classic.

First, we need to build a wall, then we place strikethrough plants behind the wall and watch them obliterate the zombie hero.

Use:

power flower

boomerang 

fume shroom

jack o lantern

Oh, and laser bean too.

but Power Flower is way better if that's all you are looking for? 😕

That would only be 4 cards with strikethrough. We need more