Tricolor Sweet Potato Vine is a great addition to large combination planters and flower beds.  It has green and white leaves that are edged in pink and has a trailing habit.  It is not as aggressive as Marguerite or Blackie but if it becomes too large for your garden spot, it can be cut back as needed to control its size.  Its also makes it a wonderful annual groundcover in the landscape.  This plants loves the heat and humidity and is very low maintenance.