If your clients have the property and the patience, there’s an appealing selection of bulbs that reseed and create naturalized landscapes without the risk of invading the neighbors’ lawns.

The six-petaled stars of Ipheion uniflorum ‘Rolf Fiedler’ (Rolf Fiedler spring star flower) are long lasting from early through late spring.
All photos courtesy of Brent and Becky’s Bulbs.

Are you lucky enough to work with property owners who aren’t driven by a need for instant gratification? A “naturalistic” plan could be just the ticket. Meadows and woodlands provide graceful, serene environments that are rendered even more appealing with the addition of bountiful bulbs that emerge and bloom, then settle in for the season – only to emerge again and spread to create a pleasing carpet or river of color. For a low-maintenance and native-style installation, there’s a wide variety of bulbs that naturalize to create swaths of color and groundcover, often extending the season of bloom from early spring through fall. And they’re well behaved, so there’s very little risk of invasiveness.

What is “naturalizing”?

According to Becky Heath, owner of Brent and Becky’s Bulbs in Gloucester, Va., “naturalizing is interpreted by so many in so many different ways. For us, naturalizing means coming back year after year by seed, spreading and making bigger clumps.”

Essentially, the naturalizing bulbs you plant today will, in time, multiply and spread throughout a landscape. For many, that may be a lawn where bulbs provide a welcome swath of color in spring. Heath cautions, however, that in order to encourage bulbs to naturalize, the lawn they embellish must be relatively free of chemical input. “Lawn often means lots of nitrogen and herbicides, pesticides, that kind of thing to make the lawn perfect all the time,” she explains. “If that’s the kind of lawn you have, even if you have a bulb that will reseed in your garden, it will not reseed in the grass because those herbicides and pesticides will keep the seeds from germinating.” It’s likely, though, that the client who desires a naturalized garden understands this and appreciates the progression of an ever-evolving landscape.

Try something a little different

Many common bulbs are used to naturalize a garden, and their brilliant colors are a welcome sight after a long, drab winter. “There are tons of bulbs for shade; there are other things for a sunny meadow,” Heath says. “You could start with crocus and then go with early into mid- and into late daffodils. The botanical or nonhybrid daffodils will reseed when they’re in their happy spot; for instance, Narcissus poeticus var. recurvus in the North. N. ‘Flore Pleno’ may also set seed and reseed in the South, because they are more prone to do that in those areas. Even some of the species tulips are happy in those types of situations.”

The dramatic foliage of Arum italicum (Italian arum) highlights the shady, woodland garden.

But Heath recommends a number of less expected bulbs to add a bit of spice to a naturalized setting. She cites the impressive spring display at Colonial Williamsburg, where Ipheion is allowed to weave its way through the landscape. Known as spring starflower – so named for its six-petaled, star-shaped flowers – this reseeding bulb blooms in hues ranging from pale to dark blue and from pink to white, appearing in early to late spring. Ipheion uniflorum ‘Rolf Fiedler’ features rich, deep blue blossoms that are sweetly fragrant. Grass-like foliage helps it to establish itself as part of a lawn, and it’s quite pest-resistant; when the foliage is crushed, it emits a garlicky or onion-like scent. Spring starflower is happy in both full sun and part shade in zones 4 through 9.

Triteleia (triplet lily) may be related to spring starflower, as Ipheion once was classified as Triteleia, as well as Brodiaea. Featuring large, dark blue, up-facing flowers on tall stems (reaching to 24 inches!), T. laxa ‘Queen Fabiola’ blooms in early summer in full sun or partial shade. “Triteleia are nice in the shade,” Heath says, and in her Zone 7 garden in Virginia, “it’s a fall bloomer. It comes up on naked stems and then its leaves come up after [bloom] and stay there through winter.”

Galanthus nivalis (snowdrops) are among the bestloved heralds of spring, often emerging while snow is still on the ground.

Galanthus (snowdrop) is also a good choice for shade. As Heath says, however, “I don’t think they are the instant gratification bulb, like people think of daffodils and tulips. I think they are more like people; they get better as they age.”

Galanthus nivalis blooms in winter and early spring, depending on the location; they’re generally hardy in zones 3 through 8. Among the first to arrive, they often emerge while there’s still a bit of snow on the ground. The bell-shaped, white blooms whose inner segments are often tipped with green are fragrant, and they nod atop slender stems reaching to about 8 inches.

If you’re looking for a naturalizing groundcover with impressive foliage, Oxalis (shamrock) is an excellent choice for sites ranging from full sun to full shade. Oxalis does produce flowers, and O. tetraphylla ‘Iron Cross’ features charming, small, carmine blooms. But, of course, easy-to-grow shamrock is best known for its distinctive leaves. “Certainly oxalis will get more flowers if they have the sunlight,” Heath explains, “but most people plant oxalis not for the flowers, but because of the color of the leaves.”

Resembling an oversized lily of the valley, Leucojum aestivum ‘Gravetye Giant’ can reach up to 18 to 24 inches tall.

‘Iron Cross’ bears green, four-leaved clover-like foliage, each with a deep, reddish purple mark that forms a cross shape. It’s not quite as hardy as many bulbs, preferring zones 7 to 10, but it’s adaptable and makes a suitable “shoes and socks” plant when combined with larger bulbs or perennials.

Not to be outdone, Arum italicum also offers distinctive foliage in shady landscapes. “It’s awesome,” claims Heath, “and you’re talking shade. It’s probably one of most successful shade plants we have, because it’s actually a three-season plant. It has beautiful green leaves with white variegation all winter long. And then in the springtime there’s a kind of greenish yellow, jack-in-the-pulpit type flower. In the summertime they have stems covered with red berries.” The berry-covered stem is actually the spadix part of the flower. The plants grow about 12 to 18 inches tall and wide and spread by tubers in zones 5 to 9.

Oxalis is an excellent choice for a groundcover or accent, filling in without becoming invasive. The foliage of Oxalis tetraphylla ‘Iron Cross’ (Iron Cross shamrock) features a distinct cross shape at the center of its leaves.

One bulb Heath recommends to more experienced gardeners is Fritillaria meleagris (checkered lily or snake’s head fritillary). “We have found that they do best in a spot that’s similar to that for Leucojum,” she explains. “It’s shadier, its soil is heavier and moister, but the heaviness is because the soil’s very, very rich. When this plant is happy, it’s unbelievable.” In mid-spring, solitary, 2-inch-long, bell-shaped flowers emerge atop 12- to 24-inch stems – and they’re among the most unusual blooms to be found. Ranging from reddish brown to purple to near black – and even white – the flowers display a distinct checkered pattern. Shown below in a meadow planting, F. meleagris also does well in rock gardens and woodland settings in zones 4 to 8.

Come fall, Colchicum (autumn crocus) blooms to brighten the waning garden. It’s not really a crocus, but it’s so named because its cup-shaped flowers on naked stems resemble the spring-blooming bulb. In late spring, Colchicum produces hosta-like foliage that fades and goes dormant during summer; flower stems begin to emerge in late summer. The cultivar ‘Waterlily’ has the appearance of its namesake, with pinkish purple to mauve, double-petaled blossoms that rise to about 6 inches tall. Autumn crocus prefers full sun to part shade in zones 4 to 8.

Naturalizing in the high country

Bulbs like hot, dry conditions; after all, many originated in the Mediterranean, where they bake happily in the summer and then snuggle in for a cold dormant season. It’s only natural, then, that there are a few glorious selections that are perfect for mountainous regions in the U.S., too. In fact, a couple of them are native to the West, and they just happen to like a very dry, very harsh climate.

Heath recommends these selections. Calochortus (mariposa lily) can be found in wild areas throughout the Rockies and points west, and its cultivated cousins do very well in challenging high country conditions. As a rule, they prefer sunny, well-drained locations with a bit of moisture in the winter and spring, but they are happiest when the summers are sunny and dry.

Variations of Calochortus offer a fascinating range of flower shapes – some including an iris-like beard – that grow to about 2 to 3 inches and appear in early summer. The species C. superbus, pictured above, features cuplike blooms in colors from white to yellow and even lavender, each with dramatic and colorful spots highlighting the base of each flower. Very narrow, swordlike leaves grow along thin but rugged stems, which can reach up to 30 inches tall.

An unusual selection can be found in Dichelostemma, the flowers of which can vary from near-allium in appearance to tubular blooms. D. congestum bears rounded, lavender-purple florets about the size of a silver dollar, which float atop slender, 18- to 24-inch stems. Blooms appear in late spring in zones 5 to 8.

Pair D. congestum with its relative, D. ida-maia, for a spectacular color combination (shown here). This species produces clusters of brilliant red, tube-shaped flowers that sport yellowish green tips. The blooms seem to dance on the tips of thin but sturdy stems that reach up to 24 inches. Like D. congestum, this striking plant blossoms in late spring.

If your clients are struggling with traditional bulbs, these are sure to please. As Heath says, “Here’s something I say quite often: Don’t fight Mother Nature. Find out what works in your area, and go with it.”

Finally, there are two groups Heath recommends highly. For an impressive touch of blue, she suggests Hyacinthoides hispanica ‘Excelsior’ (‘Excelsior’ Spanish bluebells). It is darker than most of its cousins, and it grows a bit larger, reaching up to about 12 inches. ‘Excelsior’ blooms in the late spring in full sun or part shade, preferring a bit of shade in the South. Allowed to reseed, Hyacinthoides will create lush, naturalized woodland meadows and “rivers” throughout the landscape in zones 4 through 10. Sturdy stems and the rich color of the flowers make this an excellent choice for cut flowers.

Last, but certainly not least, Heath recommends Leucojum (summer snowflake). “Over the past 20 years, whenever somebody had asked what’s the most underutilized bulb, I’ve always said Leucojum aestivum,” Heath states. “The Leucojum keeps throwing out those bells; they just stay in bloom such a long time. In my experience, the first year they were nice. In the second year, they were better. In the third year they were awesome, and in the fourth year they were to die for. And the fifth year it was like, oh my gosh, what is that? I mean, it just got better and better and better.”

California native Triteleia laxa (formerly Brodiaea laxa) produces bell-shaped blooms that turn their faces upward in early summer, often on leafless stalks. ‘Queen Fabiola’, seen here, forms loose clusters of bells on stems that reach 20 to 24 inches tall.

L. aestivum ‘Gravetye Giant’ is a large, robust clone that looks like lily of the valley on steroids. Reaching to 2 feet tall or taller in zones 4 to 8, this cultivar does well in full sun or part shade. In April to May, flowers emerge as showy, fragrant, nodding white bells that are delicately tipped with dots of light green.

Fritillaria meleagris, also known as guinea hen flower, boasts eye-catching and unusual blooms that are boldly checkered. Ranging from reddish purple to near black-and pure white-these nodding bells love meadows, rock gardens and woodland settings.

Heath says that Leucojum “naturalizes better in richer, damper and a little shadier soil, but I have them in full sun in my regular border. And then we have them in an area near our pond, where we didn’t think anything would grow, and they’ve made their own little river. Those two groups – Hyacinthoides and Leucojum – are so underutilized, but they’re so adaptable.”

One of the most adaptable bulbs, Hyacinthoides hispanica (Spanish bluebells) is happy in full sun to shade. Shown here is H. hispanica ‘Excelsior’, which features rich, regal blue flowers.

Allowing plants to redesign the landscape may be counterintuitive to a professional designer, but the results are bound to fascinate as each successive year brings a new look to the naturalized garden.

Extending the bloom season into fall, Colchicum is often called autumn crocus-although it’s not a crocus at all. The pink flowers of ‘Waterlily’ closely resemble a double-petaled water bloomer.

Becky Heath is the owner of Brent and Becky’s Bulbs in Gloucester, Va. She can be reached at info@brentandbeckysbulbs.com. Sally Benson is the editorial director of American Nurseryman; she can be reached at sbenson@mooserivermedia.com.