Trellis Shrubs consist of three parts: Shrubs, Trellis, and Flower Baskets.
Make matches or use boosters to on Shrubs to clear them and expose the Trellis below. Make matches or use boosters above the Trellis to remove it. Make matches or use boosters next to Flower Baskets to remove them.

Note: Flower Baskets will make Shrubs grow on empty Trellis' nearby. It's a good idea to clear the Flower Baskets first.