Trillium grandiflorum is the largest and showiest of all our native trilliums, with individual flowers that can be more than 3 inches in diameter. It is a slow-growing, but long-lived, plant that takes four to five years to mature sufficiently to flower but can live 50 or more years. As they age, the plants grow larger. Because of this, the best planting method is to plant mature rhizomes in the fall or early spring prior to green-up. Once settled in place, this species does not like to be moved or disturbed, so it should not be dug from the wild and replanted in the garden. In addition, this species should not be cut, because the plant will die if the leaves are removed. The very large specimens found in mature woodlands are often 70 to 80 years old.
Like most spring wildflowers, this species goes dormant during the summer and should be planted among various ferns to prevent bare spots in the beds. When purchasing rhizomes from a nursery, make sure to ask if their specimens were grown from divisions and not collected in the wild, since this species is widely collected for gardens throughout North America. Great companion plants include Southern red or Sulcate’s trillium ( Trillium sulcatum ), Virginia bluebells ( Mertensia virginica ), lady fern ( Athyrium filix-femina ), maidenhair fern (Adiantum spp.), wood f erns (Dryopteris spp.) and wild blue phlox (Phlox divaricata). Deer love trilliums, so they should be protected from browsing. Like many of the other trillium species, the seeds of Trillium grandiflorum are dispersed by ants and, thus, they are not likely to escape cultivation nor reproduce quickly, which allows gardeners and landscapers the opportunity to design more formal woodland wildflower gardens.
Common Name: Large-flowered trillium, large-flowered wake robin, white trillium
Botanical Name: Trillium grandiflorum
Color: White with petals fading to pink as they age
Blooming Period: Spring
Type: Perennial wildflower
Zones: 3 to 9
Size: 12 to 18 inches
Soil: Well drained, rich organic with leaf mulch to pH 6.8 or less
Watering: Frequently until established, then liberally during summer droughts
When to Plant: Fall is the best time, followed by early spring
When to Fertilize: After frost, a light cover of composted leaf mulch
In Your Landscape: This is one of the showiest of all spring ephemeral wildflowers and makes quite a statement when planted en masse with other spring wildflowers interspersed.
From Kentucky Gardener Issue X Volume IX. Photos courtesy of Thomas Barnes.