by George Papadelis
For hundreds of years, this plant and its name have been used to symbolize purity, simplicity, elegance, and beauty. The name trillium has graced the marquees of restaurants, country clubs, resorts, software companies, consulting firms, and numerous other businesses. Every spring, many Americans journey into the woods to admire the showiest of our spring woodland flowers.
In Ohio, where all 88 counties have masses of wild trillium, it was selected as the state’s official wildflower. Its flowers have twice graced a U.S. postage stamp. Even our Canadian friends across the bridge have declared white trillium (Trillium grandiflorum) the official provincial flower of Ontario. Other parts of the world share our passionate admiration for this plant. In Europe, where trilliums are not found in nature, gardeners dedicate vast amounts of time and money acquiring them, especially rare species. In Japan, a cult-like interest has developed towards trillium.
Trillium species and growing conditions
The most readily available species is Trillium grandiflorum or white wake-robin. This has large, pure white flowers up to 5 inches across. These develop in great abundance throughout the northeastern U.S. Its flowers usually fade to a dull pink and sometimes red. Trillium erectum is a much more diverse species with flowers ranging from red to purple to yellow-green and beige. It also grows wild in the Northeast and Michigan. Trillium luteum is the most common yellow species. It originates from areas around eastern Tennessee. One of its most notable features is the beautiful dark green leaves decorated with pale green markings. The flowers are relatively small. Trillium recurvatum bears maroon-purple to clear yellow flowers with strongly curved petals. Several other species and a few named varieties are readily available. Most trillium grow about 12 to 18 inches tall once established in the garden.
Trilliums are North American and Asian natives that typically thrive in moist, woodland settings where rich, acidic soil is prevalent. Gardeners with some shade can create this type of soil by incorporating organic soil amendments such as aged pine bark, sphagnum peat moss, leaf mold, composted manure, or compost. During dry spells, plants may require some supplemental watering.
Trilliums typically bloom in late April or early May when dozens of perennials and bulbs are available as companions. Several spring-flowering bulbs will tolerate shade, and a few flower at the same time as trilliums. Try trilliums with daffodils, tulips, Siberian squill, grape hyacinths, summer snowflakes, glory-of-the-snow, and Anemone blanda. Pansies and violas planted the previous fall or in early spring will offer the largest color range to coordinate with your trillium flowers. Early May-blooming perennials for shade include Anemone sylvestris, foamflower (Tiarella), fern-leaf bleeding heart, leopard’s bane, and the beautiful blue-flowering perennial forget-me-not (Brunnera macrophylla). Several other woodland plants such as woodland phlox (Phlox stolonifera) and yellow dogtooth violets (Erythronium canadensis) should also be at peak bloom.
How trilliums grow
As gardeners, many of us have developed questions about growing this somewhat mystical plant. It doesn’t help that the typical nursery only sells tiny, flowerless plants that show little promise of ever coming to fruition. Perhaps the most important aspect of appreciating this plant can be expressed in one word: patience. The small plants available through nurseries are much more durable than they appear. Most species will eventually develop into clumps of flowers that are quite persistent even in less than perfect conditions. This clumping process often takes 2 to 4 years. At least it’s faster than growing them from seed. If the seed germinates, it may take as long as 10 years to bloom.
Another perplexing aspect of growing trilliums is the short period of time plants are visible in the garden. The “root” of a trillium is really a sort of underground stem called a rhizome. This rhizome stores food all winter until temperatures rise in spring. In early May, the rhizome sends up branches that typically support three leaves and a single three-petal flower. The short time during which leaves are present is the plant’s only chance to gather energy from the sun. Therefore, picking trillium flowers and leaves will diminish the plant’s ability to produce food. It won’t kill a healthy plant, but frequent picking will eventually reduce flowering. The number of flowering branches depends on the age of the plant, the size of the rhizome, and the overall energy stored in the rhizome.
Next comes the strange part. Just a few weeks after blooming, the branch and leaves wither away with no visible signs of life. The rejuvenated rhizome will await winter dormancy, which is mandatory for next year’s bloom production. Many woodland plants and spring-blooming bulbs (i.e. tulips, daffodils, crocus, etc.) enter an early-summer dormancy. These plants, like trilliums, are described as spring ephemerals. If you are thinking of shopping for a potted trillium in summer or fall, visually evaluating a plant’s vigor is almost impossible. However, a gentle probing of the soil to locate a firm, sleeping rhizome should do the trick.
Finding and purchasing trilliums
Some trillium species are considered threatened or endangered. These trillium cannot be collected from the wild under any circumstances. All other trillium in Michigan are protected as follows: The only way these can be collected is by owning the land from which they are harvested, acquiring a permit to collect them from the Department of Natural Resources, or by acquiring a bill of sale from the property owner. All trillium located in National Forests are also not collectible.
Since it is legal to collect unthreatened and unendangered trillium that are located on your own land, “nurseries” can own land from which they may legally collect wild trillium. Fortunately, responsible commercial collection of trillium has had little effect on most species. Most trillium have developed stable masses in their natural habitats, and more and more nurseries are offering wildflowers that are propagated on site. As gardeners and stewards of our environment, we should seek out these sources and avoid plants that are illegally collected.
The biggest two concerns for the sustenance of trillium populations are animal grazing and urban development. Repeated grazing from deer can eventually weaken plants and wipe out large areas. In regions where deer populations have increased, trilliums have often disappeared. A deer repellent would be a wise investment if deer browse in your trillium bed. In cases where a plant’s habitat is limited, populations are also suffering from commercial development. Clear cut lumbering and urban sprawl have an enormous impact on all wildflowers. In cases where development is unavoidable, the proper agencies should be contacted to save important plants. A great source of trillium is one that has a permit to rescue plants that would otherwise fall victim to bulldozers.
Trillium are available from many garden centers as spring-flowering plants in small containers. These can be treated just like any other perennial. More and more retailers are selling them packed in plastic bags with some peat moss. Make sure the rhizomes are firm and try to plant them before the leaves emerge. Bury rhizomes horizontally about 2 to 4 inches deep in the moist, rich soil that most woodland wildflowers love.
Remember to be patient—good things come to those who wait. In time, your little plant should form colonies that you and your garden’s admirers will enjoy for years to come.
George Papadelis is the owner of Telly’s Greenhouse in Troy, MI. Fred Case and Tony Reznicek also contributed to this article. A portion of this article was excerpted from the book “Trilliums” by Fred Case and Roberta Case, published by Timber Press.
At a glance: Trillium (TRILL-ee-um)
Plant type: Perennial
Plant size: Most are 12-18 inches tall and 12 inches wide
Hardiness: Most are zone 4 or 5
Flower color: White, red, pink, yellow
Flower size: Up to 3 inches wide
Bloom period: Late April to early May
Leaf color: Green, sometimes mottled with pale green, dark green, or maroon
Leaf size: Up to 8 inches long and up to 6 inches wide
Light: Dappled shade to shade
Soil: Moist but well-drained, rich in organic matter
Uses: Woodland garden, shady border
Companion plants: Spring-flowering bulbs (daffodils, tulips, grape hyacinths, etc.); spring-flowering perennials (foamflower, fern-leaf bleeding heart, perennial forget-me-not, woodland phlox, etc.)
Remarks: Patience is a must—trilliums take time to become established; the plants go dormant in summer (stems and leaves naturally wither away)