Broken Cannons.

[McDonaldsHadFire]

So I Was Playing Pirate Seas Day 15, I Finished It And Only The Cannons Were Left So I Wait And The Imps Get Shot Over The Flowers.

Help?

[wadebear]

Don't use Cannons.  There, that was easy.

Seriously though.  You need to knock out the Imp Cannons as quickly as possible.  The real secret to surviving any level is to delay the first few zombies as long as possible to allow time to build up Sun.  Then you can build stronger plants that will take out more zombies.

If you really get stuck try doing a Google search for the level.  There are numerous ways to get through that level depending on which plants you have.