When bulbs' brief but glorious season is upon us, we want to revel in it. Naturalized planting lets us do just that. Naturalizing is planting informal "drifts" of dozens or even hundreds of bulbs among other plants. With time, the bulbs multiply and spread into a spectacular display of flowers with minimal work and minimal damage to your budget. Lightly wooded areas, lawns, and rock gardens are the most popular places for naturalizing.
Spots for naturalizing
In lawns. As more gardeners embrace naturalistic gardens, they've embraced naturalizing bulbs, according to Sally Ferguson, director of the Netherlands Flower Bulb Information Center. "One emerging trend is sweeps of color in the lawn, especially of blue flowers."
Lawns have become the spot of choice for naturalizing many smaller bulbs including crocuses, scillas, Ipheion, Spanish bluebells, grape hyacinths, and snowdrops. (For the sake of brevity, all the plants in this article are referred to as bulbs, although some, such as crocuses, are botanically corms, tubers, or rhizomes.) More homeowners are planting drought-tolerant turf grasses that green up later in the season, and they find that their lawns cry out for a little early-season color in the form of masses of bulbs.
Small early bloomers are also well suited to lawns because they grow about the same height as the grass. Their foliage conveniently browns and ripens right about the time a first mowing is necessary, though you'll probably have to let the grass get fairly long before you can cut it. (The foliage on nearly all bulbs must be allowed to brown thoroughly before removing, because it replenishes the bulb for next year.)
Larger, later bulbs, such as daffodils, don't ripen until the grass is quite high—which isn't good for the grass and doesn't give the neat look many homeowners want. Instead, Ron Cornwell, a horticulture extension educator for the University of Illinois, Madison County, likes to plant daffodils along a fence where he can allow the grass to grow very long into late spring as the foliage ripens. He finds the effect relaxed rather than neglected.
One thing to keep in mind when planting: Scott Kunst, owner of Old House Gardens, a mail-order supplier of heirloom and antique bulbs, warns that if the turf is very thick and very healthy, it may hinder the spread of some bulbs by acting as a living mulch.
Under trees. Bulbs naturalize just about anywhere. A classic combo is spring-blooming bulbs under deciduous trees, particularly in woodland areas. (In smaller yards, this might be under a large tree.) The bulbs bloom before the trees leaf out, so they have plenty of sun while actively growing. If your trees have shallow root systems, plant some of the smaller bulbs, which seldom need to be planted more than 4 inches deep and often can be planted as shallowly as 2 inches. Ferguson puts small bulbs under crape myrtles, magnolias, and dogwoods, as well as under tall flowering shrubs.
Other places. Fields and meadows are a traditional place to naturalize bulbs. Most bulbs are natives of mountainous areas with arid summers, so it's critical that any meadow or open grassland isn't too soggy and that you don't plant in moist, low-lying areas. Bulbs require excellent drainage and can easily rot in wet summer or autumn conditions.
Because drainage is so important, slopes and rock gardens are other ideal places for naturalizing. This makes them an unconventional but beautiful addition to drought-tolerant prairie plantings as well. They also love sandy and gritty soils.
Still, there are exceptions to every rule. Camassia, a North American native of marshes and bogs, has beautiful blue flowers and naturalizes well in wet conditions, even those with heavy clay, including areas along creeks and ponds.