Part of the art of naturalizing your bulbs is to balance the formal aspects of your garden—and extend it. Where strict borders of daffodils or tulips may produce a lovely, sculpted effect, a naturalized area nearby gives an aura of carefree grace, an invitation to interact more fully with your garden than merely to observe its floral display.
Tulip companions are a must, then, to give your naturalized plantings an air of casual charm; unmixed tulip groupings are simply too stiff and formal for the wild look. The hardy wood hyacinth Hyacinthoides hispanicus, or Spanish bluebells, makes an unusual yet worthy tulip companion. Its high stalks are laden with bell-shaped blossoms in blue, pink, or white. 'Excelsior' is a hardy variety, with a subtle blue color.
Then there is camass, hardy to Zone 2, fine in sun or partial shade, amenable to lots of water during flowering, yet resistant to drought after blooming. By the time your tulips bloom, camassia's 2.5-to 3-foot-high stems are hung with delicate thin-petaled flowers in baby blue with accenting yellow stamens. Their effect softens and harmonizes with even the most vivid tulips. For naturalizing, Camassia Cusickii is the variety of choice.
As a general rule, bulbs are planted at a depth of about three times their height. But research has found that planting tulips 8 rather than 6 inches deep tends to increase their life span significantly.
Generally, you need to plant bulbs, in shade or full sun, before your area's first hard frost—September, October, or November in most areas north of the Mason-Dixon line and below the line as far south as Georgia and Arizona and in the Pacific Northwest. Further south, plant in the shade in October, November or December. Again, well-drained soil is the crucial factor, along with choosing bulbs appropriate for your area and for naturalizing. Find sites for them that showcase their wild charms, and enjoy a spring-after-spring celebration of natural gardening at its colorful best.