Filled with annuals, perennials and roses, this would be a traditional garden in a typical backyard. Filling the same space with symmetrical rows of grasses and shrubs creates a completely different look.Though hardscaping may play a leading role, plant choice is still a major factor in a modern or contemporary landscape. Ideally, most should have an architectural character (think phormium or blue fescue) with foliage in shades of green or gray. Though colorful flowers and plants can be used in this style of landscaping, they're most effective when treated as accent pieces.