1261 Trillium grandiflorum

Description

This is not the only white flowered trillium, but it is the most spectacular. All trilliums have a single stem with three whorled leaves and a single conspicuous flower that has three petals and three sepals. Great white trillium is a robust spring ephemeral with sessile leaves 4-10 in (10-25 cm) long. The whole plant can be as much as 18 in (45 cm) tall and spread 18 in (45 cm) or more across. The waxy white flowers that appear in mid-spring are held on 3 in (7 cm) stalks above the leaves. The inflorescence has three conspicuous green sepals and three egg shaped, wavy edged petals to 3 in (8 cm) long. The flowers (unscented) fade to a rosy pink as they age. Great white trillium produces green or maroon berries a couple months after flowering. By late summer the entire plant has disappeared and it remains dormant, beneath the surface, until the following spring.

The cultivar ‘Flore Pleno’ has double flowers, and the botanical variety, roseum, has bright pink flowers.

Location

Trillium grandiflorum occurs naturally in rich, mesic hardwood forests and forest edges from Quebec, south throughout the Appalachian Mountains to northern Georgia, and west to Minnesota, Missouri and eastern Tennessee.

Culture

Light: Like other trilliums, great white trillium grows where there is partial to deep shade in the summer, and partial sun to full sun during the early spring while the deciduous trees overhead are still bare. Moisture: Great white trillium likes a neutral to slightly acid soil that is rich in organics and humus. The soil should be moist, but not soggy. Supplemental watering may be needed during dry periods in spring. Mulch heavily with leaf mould. Hardiness: USDA Zones 4 - 8. Propagation: Trillium seeds should be sown as soon as ripe and will take two years to germinate. Plant them in a moist, humus rich medium and allow them to overwinter outside. Great white trillium grown from seed needs 7-10 years to reach flowering size. The rhizomes of mature plants can be divided, but even these are slow to get going. Another approach is to cut out the tip of the rhizome where growth begins; this stimulates the formation of offsets. You can also try cutting a groove along the length of a rhizome with a sharp knife; this should stimulate the formation of offset plantlets as well. These vegetative methods of propagation should be attempted only when the plant is dormant.

Usage

This is a spring ephemeral - a forest dwelling plant that does its growing and flowering in early spring before the deciduous trees have captured the sunlight. Position this and other Trillium species in shade beneath hardwood trees, or in a shady border where the soil is rich and moist. Trilliums are great for naturalizing in a woodsy garden along with ferns and other spring ephemerals such as bloodroot, (Sanguinaria canadensis), Solomon’s seal (Polygonatum odoratum), wild columbine (Aquilegia canadensis), Dutchmen’s breeches (Dicentra cucullaria), trout lily (Erythronium spp.), and Virginia bluebells (Mertensia virginica), among others. Trilliums can be expected to spread slowly on their stout, subterranean rhizomes. If you are fortunate enough to find some great white trilliums at your favorite native plant nursery, you will be richly rewarded with the ephemeral spring magnificence of this rare delight.

Features

The trilliums were formerly placed in the family Liliaceae, a huge amalgamation that contained some 300 genera and 4,500 species. The family has since been subdivided and the Liliaceae now has just fifteen genera and approximately 600 species. The Melanthiaceae, which includes the trilliums, has some 17 genera and around 650 species. There are about 30 species of Trillium, most of which are native to North America, with a few occurring in the Himalayas and northeastern Asia.

Warning

Trillium grandiflorum is listed as Endangered in Maine, Vulnerable in Quebec, and commercially exploited in New York. Note that unscrupulous dealers may be selling plants that were collected (illegally) from the wild. Great white trilliums collected from the wild almost never survive.

Steve Christman 5/19/16