Many gardeners use the concept of "thriller-filler-spiller" when building their summer baskets and container planters, but as is true with any simplified idea, it's not always black and white. Calibrachoas, also known as Million Bells, can fulfill all three functions, depending upon the size of the planters, the specific varieties used, and what you choose to combine with them. 'Superbells Holy Moly' is a standout in baskets and container planters, mounding up to a foot tall, then cascading gracefully over the edges. Its vibrant two-tone flowers make it a great accent in mixed baskets, complementing darker flowers for a dramatic look or light/white colors for a bright summery feel. Place calibrachoas in a sunny location, and water and fertilize regularly for beautiful blooms right up until frost.