Many of the bulbs we grow and enjoy in our gardens, including tulips, daffodils, crocus, hyacinth, and snowdrops, are native to other parts of the world, specifically the Eurasian content. This includes the mountains of Europe and Asia as well as the Mediterranean. There are, however, a few species native to North America. These species are found largely in the western areas of the continent, but there are species growing in most areas.
The species listed below are native to North America. The term "bulb" is used in the broadest sense to include any fleshy underground structure, including true bulbs, corms, tubers, and fleshy rhizomes. Consider trying one of these species in your garden.
Camas | Lilies | Ornamental Onions | Trout Lily | Mariposa Lily | Other Species | More Information
Camas
Camas (Camassia), also called Indian hyacinth and quamash, is a genus comprised of six bulbous perennial species that have great value in the ornamental garden. Blue to blue-violet flowers (sometimes lavender or white) appear in May or June. The star-shaped flowers are arranged along a long stalk that arises from a tuft of foliage that often doesn't look the greatest. This makes them good candidates for the middle or back of the perennial border. Leaves die back after flowers fade, and plants remain dormant until the following spring.
Plants naturally grow in moist open meadows and grow best in fertile, well-drained, but consistently moist soils. Plants don't mind being a little on the wet side, but cannot thrive in overly saturated soils or standing water, especially over winter. Grow in full sun or part shade (they are particularly fond of protection from the late-day sun). When happy, plants readily multiply or naturalize.
Several species are particularly well-suited for garden settings. Plant bulbs in fall. Despite being winter hardy, plants generally benefit from a mulch layer over winter to provide some extra protection, especially that first winter.
Quamash
Quamash (C. quamash) is also known as small camas or Indian camas. This species was used as a food source for several Native American groups in western North America. Bulbs would have been harvested in the fall and either boiled or roasted. Flowers appear in June on 18-inch tall stalks. Cultivars like 'Blue Melody' and 'Orion' have nicely colored flowers.
Large Camas
Large or greater camas (C. leichtlinii) is much taller than quamash, growing 2 to 4 feet tall and blooming in late May or early June.
Atlantic Camas
Unlike other species, Atlantic or eastern camas (C. scilloides), is native to the eastern side of North America. This species is also called bear grass and wild hyacinth. Light blue flowers form on 18" tall spikes in June. Leaves are much more grass-like.
Cusick's Camas
Cusick's camas or quamash (C. cusickii) grows 2.5 feet tall and blooms in May or June.
Death Camas
Not directly related to camas, but similar in appearance, death camas (Zigadenus elegans) occurs throughout the native range of camas and is easily confused. This is important to note as true camas (Camassia) is edible, whereas death camas is highly poisonous. Flowers appear in summer and consist of white, star-shaped blooms arranged along a tall stalk 2 to 4 feet tall.
Lily
The true lily (Lilium) is a well-recongnized and common bulb. Many of the classic garden lilies featured in our gardens, like Asiatic hybrids, Oriental hybrids, Easter lily (L. longiflorum), and Turk's cap lilies (L. martagon), are native to Asia and parts of Europe. However, there are several North American native species well suited for the garden.
Learn more in these articles: Growing Garden Lilies (PDF) and American Lilies from the Pacific Bulb Society.
Meadow Lily
Meadow lily, also known as Canada lily (Lilium canadense), is native to a wide swath of eastern North America. Plants have 3-inch-wide, yellow to orange tepals (petals) with dark purple spots on 3 to 6-foot-tall stems. Flowers are pendant and somewhat bell-like. Plants love the woodland edge and will tolerate part shade, growing best in consistently moist, but well-drained soils.
Most of the "American Hybrids" found in garden centers are hybrid selections of crosses of this species. Popular cultivars like 'Buttercup' and 'Shuksan' are members of this hybrid group.
Wood Lily
Native to a wide range of eastern North America, including parts of Iowa, the wood lily, also called prairie lily (L. philadelphicum), has upward-facing red to orange-red flowers 3 to 4 inches wide in summer. Plants grow 1 to 3 feet tall and tolerate a wide range of soil conditions.
American Turk's Cap Lily
American Turk's Cap Lily (L. superbum) blooms in mid to late summer with numerous downward-facing facing orange-red flowers with dark spots. The tepals recurve back so they touch behind the bloom. This lily makes a statement when in bloom on top of 4 to 8-foot-tall plants. Don't confuse this species with Turk's cap lily (L. martagon), which is native to Eurasia. However, they do thrive in very similar growing conditions - full to part sun and consistently moist, but well-drained soils.
Columbia Tiger Lily
Often called tiger lily or Oregon lily, Columbia tiger lily (L. columbianum) has nodding orange flowers with reflexed tepals covered in dark spots. Blooms appear on top of 5-foot stems in early to midsummer. Plants are native along the western North American coast from northern California through British Columbia.
Ornamental Onions
Most ornamental onions (Allium) are native to the Mediterranean and central Asia, but there are several species that can be found in western North America, in particular California. Most of the 100+ taxa of the Allium genus found in North America are not well-represented in the horticulture trade, making them unlikely to be found in nurseries and garden centers.
The most popular species and consequently the one most likely to be found in the garden center is the nodding onion (Allium cernuum). This species has a unique nodding umbel of lilac-pink flowers that appear in early summer. The foliage gets approximately 18 inches tall and persists into late summer.
Other species include one-leaf onion (Allium unifolium) with large star-shaped flowers in a larger umbel. Despite its common name, each bulb typically sprouts two to three flat leaves. Other species you occasionally come across in native plant nurseries include prairie onion (Allium stellatum) and meadow garlic (Allium canadense). Nearly all of these species can be prolific reseeders and will be quite weedy. If self-sowing becomes an issue, deadhead immediately after flowering.
Learn more in these articles: All About Ornamental Onions and American Alliums from the Pacific Bulb Society.
Trout Lily
One of our favorite woodland wildflowers, trout lily (Erythronium americanum) is a lovely addition to the shade garden. Mottled green leaves emerge in spring, followed by solitary yellow flowers with six petals (more accurately called tepals) that curve back. Plants are small, reaching 3 to 6 inches in height, and are mainstays in the eastern deciduous forests of North America, including wooded areas of Iowa.
Mariposa Lily
As a group, mariposa lilies (Calochortus) are enchanting bulbs native to California and other parts west of the Rockies. They are notoriously difficult to grow in the Midwest, but if the right conditions can be created or found, they will reward gardeners with lovely flowers in spring and early summer. Flowers are tulip-like and typically upward facing with three petals, often featuring prominent markings (that sometimes resemble that sometime resemble the markings of a bearded iris. The foliage is narrow and grass-like.
These bulbous plants grow best in full or part sun and perfectly drained soil. Soil conditions are the key to success, and creating those ideal soil conditions in the Midwest is difficult. Mariposa lilies need exceptional drainage but also benefit from consistent moisture - think of it as the difference between a shower and a pool - both are quite wet, but they are very different experiences. Mariposa lilies want to be in the shower, not the pool! Amending the soil with coarse grit or sand along with some organic matter can create the ideal soil conditions. They grow naturally in areas that are dry over the summer months, so providing dry conditions in summer is also important. This makes them great additions to rock gardens. Just be sure they are not situated near plants that need supplemental irrigation. Some gardeners have success planting them near ornamental grasses, which can soak up all the extra moisture, keeping the dormant bulbs dry in summer.
Winter hardiness is the other challenge in growing mariposa lilies in the Midwest. Many are winter hardy to USDA Hardiness Zone 5, but they do not tolerate wet winter soils and the freeze-thaw cycle that often happens over winter. Protect the area by placing mulch, coarse leaves, or pine boughs over the planting area after the ground has frozen. This insulating layer helps moderate and prevent the freeze-thaw cycle.
As is clear, this is not a bulb for the novice gardener, but can be a wonderful adventure for a gardener looking for a new challenge. Species to consider include Yellow Mariposa Lily (Calochortus luteus), which is often touted as the easiest to grow species. Proud mariposa (C. superbus) has white to lilac petals with distinctive yellow blotches at the base of each petal. Butterfly mariposa (C. venustus) has white petals with bold maroon and yellow markings at the base of each petal. Sagebrush Mariposa Lily (C. macrocarpus) has purple flowers with a central green stripe. Elegant Cat's Ear (C. elegans) has unique hairy white petals with a lovely purple base.
Other Native Species to Consider
There are many other species that grow from bulbs, corms, tubers, or other fleshy underground structures. Many are familiar ephemeral species found in woodlands. There are several other bulb species native to North America, but not always easy to find in commerce. Both the easy and hard-to-find species are listed below. All of them are species or genera with species that are winter hardy to at least USDA Hardiness Zone 5. If you are looking for something different, consider some of these species:
- Spring Beauty (Claytonia virginica)
- Crested Iris (Iris cristata)
- Northern Spider Lily (Hymenocallis occidentalis var. occidentalis)
- Yellow Fritillary (Fritillaria pudica)
- Purdy's Fritillary (Fritillaria purdyi)
- Crow poison (Nothoscordum bivalve)
- Triplet Lily (Triteleia)
- Wild Hyacinth (Dichelostemma)
More Information
- Selecting and Planting Spring-Blooming Bulbs
- Native Woodland Wildflowers for the Home Garden
- Native Perennials for Moist to Wet Soils
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