A lovely collection of plants adds beauty to a yard.Place plants with contrasting colors -- hot purples and pinks versus pastel oranges -- in separate areas of a garden.Edging can be formal or informal; the former, shown in this sunny bed, provide a neater border for a garden.To draw winged visitors, offer a moving source of water, such as this pretty birdbath.Patches of annuals, such as petunias, fill in empty spots in a mostly perennial bed.Strategically placed stretches of boxwood break up