There are 3 Silver and seven Bronze trophies in the Plants vs Zombies Garden Warfare: Zomboss Down DLC. The new DlC has one new map, eight new variants, and three new potted plants Cactus Canyon was the new map of the DLC, it is a Gardens & Graveyards map.
Silver
Win 15v matches on the Gnome Bomb team
Destroy 500 Pirate Zombies
Try to Defuse a Gnome Bomb with 3 seconds remaining
Bronze
Call a Barrel Pirate and Map Pirate Zombie in Gardens & Graveyards
Defuse 3 Gnome Bombs
Kill 10 Enemies while They are Carrying a Gnome Bomb
Pick up a Gnome Bomb
Put the Golf-Bomb into the Hole in Cactus Canyon
Grow a Doom-shroom, Bamboo Shoot, Fire Peashooter and Ice Peashooter
Plant 5 Gnome Bombs
"To progress in the game, players must complete challenges unique to each class. These challenges, once completed will rank up the character allowing the player to access unique features regarding that character such as upgrades, new characters, weapon skins and character clothing. The game's challenge pop-ups closely resemble the notification system used on the Xbox One."