No spring shade garden is complete, in my estimation, without trilliums and their distinctive triads of leaves, sepals and petals. Our native Indiana trilliums are easy to grow, as long as we provide for them a setting similar to the woodlands in which they naturally occur, with seasonal moisture, shade in summer and a well-drained soil rich in organic matter.
Trilliums are available to buy online and at a few nurseries, but please make sure they haven’t been collected in the wild. Growing trilliums from seed requires patience, as a plant started thus takes five or more years to flower. After a mature trillium goes dormant in late summer, its rhizome may be divided for swifter propagation , but the laid-back gardener may be content to let ants do all the work of dispersal and propagation. Ants harvest the trillium seeds for their nutritious fatty appendages called eliasomes. The ants carry the seeds underground, partake of the attached food, and leave the remaining seeds-- effectively planting them. So give credit to the lowly ant next time you admire a forest full of wildflowers, and also to the flowering plants that have evolved such ingenious methods for both pollination and dispersal.
Our Indiana trilliums are generally either white or red. The impressive Great White or Large-flowered Trillium is perhaps the best-loved of all eastern trilliums. It holds its large ruffle-edged blossom above the leaves on a flower stem--or pedicel--and can occur in stunning massed displays. As it ages, the white flower takes on a rosy hue. This trillium, the Ohio state wildflower, is uncommon in the wilds of Indiana, and is found mostly in the northeastern counties, although it is also present in Brown County State Park.
One of our earliest local wildflowers (appearing in late February), is the diminutive but hardy snow trillium, a specialist of limestone cliffs. It can be quite showy with its pedicelate white flower, leathery blue-green leaves and reddish stem. The restricted habitat of this dwarf species makes it more challenging to grow, but according to Fred Case in his invaluable book Trilliums, it is an “outstanding rock garden plant, . . .easy to cultivate if given limestone soil.”
Two other white trilliums are less showy, holding their stemmed flowers beneath the leaves: Nodding Trillium is extremely rare, found only in the lake counties of northwest Indiana, but the rather unfortunately-named Drooping Trillium occurs in rich calcareous woodlands throughout the state—indeed, Indiana is virtually the epicenter for this common Midwestern species’ range. Despite its name, this trillium is not droopy but can be quite large and robust, with a lovely creamy –white flower that is sometimes held above the leaf plane. In a few wild populations, the petals are deep rose, and the these blooms are quite striking with their contrasting creamy-white pistils. Drooping Trillium is especially attractive when massed on hillsides, where its flowers are more visible from below.
The white-flowered trilliums are pollinated by bees and butterflies. Their odor is pleasant or mild. In contrast are the red trilliums, including the aptly-named Stinking Benjamin (T. erectum), which cater to carrion flies, beetles and gnats with their deep red color and wet-dog aroma. Stinking Benjamin, or simply Red Trillium, prefers acidic soils and is known from only a few locations in Indiana. Its stemmed flower may be erect or slightly nodding. In the Great Smoky Mountains a white or “sweet” form is quite common.
Stinking Benjamin (T. erectum), left, and the white form Sweet Trillium, right.
Scott Detwiler (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
The two red trilliums most familiar to residents throughout Indiana are less smelly and also less showy, with stemless flowers that sit atop the leaves. Rather than spreading to present a landing platform for pollinators, the petals remain upright around the ovary and stamen, inviting insects that savor carrion to crawl around inside.
Recurved, or Prairie Trillium (T. recurvatum).
More (above) and less (below) mottled individuals of Toadshade,
or Sessile Trillium (T. sessile).
Both of these common red trilliums have mottled leaves as well as upright petals, but the differences between the two species are quite apparent if you happen to catch them growing side-by-side. The Prairie or Purple Trillium is a tall slender fellow, with sepals that point down—or recurve-- between each leaf; indeed, a more accurate name for this species is Recurved Trillium (although I rather like the deliciously lurid old folk name “Bloody Butcher”). The Sessile Trillium, on the other hand, is short and squat, with sepals spread out above the leaves. Sessile Trillium is also known as Toadshade, a more fanciful name that is just as diagnostic as “sessile”, which refers to the stemless nature of the flower; after all, this trillium does grow low enough to the ground to shade a hot and thirsty toad.
The flowers of these two trilliums may vary in hue: from vibrant magenta to dull maroon, and even greenish-gold. My favorite Indiana trillium? An individual Recurved or “Purple” Trillium I visit in the wild each year--to admire its pure yellow flower.