The player has to deal with the Bobsled Zombie, thanks to Zombonis. They are difficult to get rid of since they travel on an almost damage-resistant sled on Zomboni's ice. Although they only take 200 damage each for them to die, there are four of them, which means it takes 800 damage for all of them to die.
Plant two columns of Sunflowers on the left. Use Squash to kill the first two or three zombies. Once that's over, you should have enough sun to start planting Threepeaters. Plant Threepeaters on the third column, on the tiles that are close to the pool first. Then, plant them everywhere else in the column.
Plant another column of Threepeaters.
Now, plant a column of Torchwood, and then start planting Tall-nuts in front of the Torchwoods. Also, if you have enough time, plant Spikeweeds in front of the Tall-nuts, and use them to get rid of Zomboni.