The level is easier than the other levels due to the ready amount of plants the player receives during the level.
Plant the first Threepeaters you get on the second and fifth lanes (the grass lanes closest to the pool), so it can inflict damage on zombies on every lane. Start doubling up on Threepeaters and start planting them on the outside lanes and the pool lanes.
When you think you have planted enough Threepeaters, put the Torchwood you get surrounding the Threepeaters from the outside to double the amount of damage. Then plant Tall-nuts, Tangle Kelp, and Spikeweeds on the outside.
When a Zomboni comes, use a Jalapeno or a Squash (if you do not have a Jalapeno) or use the Spikeweed to kill them instantly. Make sure to also be ready for the Bobsled Team that comes out if you do not use the Jalapeno.
Whenever you have a lot of zombies in a row (preferably on the outside lanes since they are weaker), use a Jalapeno to kill them all instantly.