For Spring, Tulip-Packed Window BoxesLarge window boxes can function as year-round container gardens. For ongoing good looks, this one is planted with a mix of permanent shrubs, perennials and vines, with seasonal color from flower bulbs and annuals added twice annually. "In spring, there's a fairytale synergy to the mix of boxwoods and tulips with blue and gold accent plants and green vines," says Oklahoma City garden designer Linda Vater. "In spring, tulips are the divas, so the bulbs are planted densely, shoulder to shoulder, across the back of the box. Colorblends Gentle Giants® tulip blend adds subtle complexity without making the entire combo too busy."