Trilliums That Bloom Once in Seven Years

Planting Trilliums

• Trilliums are native to woodland areas and grow best in garden settings that mimic their natural environment. Give them humus-rich, acidic, moist soil and dappled shade throughout the day; they'll thrive under the same conditions as rhododendrons and azaleas. As young plants can take up to 15 years before blooming for the first time, it's best to purchase flowering plants from a nursery so you know your plant is mature. Never harvest trilliums from the wild. They rarely transplant well and are considered endangered and protected plants throughout much of their range.

Don't Pick the Flowers!

• Picking trillium flowers creates a serious, sometimes fatal, stress on the plant and it takes years for the plant to recover enough to flower again. Depending on the species, that delay can last for five to seven years or more. This is the source of the old wives' tale that trilliums only bloom once every seven years.

Great White Trilliums

• Also known as snow trilliums and wakerobins, great white trilliums (T. grandiflorum) are native to the Appalachian Mountains and are found from Maine and Ontario down to Georgia and Arkansas. These early-spring flowers are 3 to 7 inches across and reach 8 to 16 inches tall, producing one flower on each stem. The flowers open clear white but turn pink as they age. These plants are quite long-lived, lasting up to 70 years; however, they don't bloom in the wild until they're 10 to 17 years old, although nursery-grown plants may bloom in as few as three years. Great white trilliums are hardy in U.S. Department of Agriculture plant zones 3 through 9.

Red Trilliums

• Found throughout the upper Midwest as well as the eastern United States, red or purple trilliums (T. erectum) have deep red petals, although the color can vary from lavender to pink. At 1 to 3 inches across, red trilliums have smaller flowers, but the stalks can reach 18 to 24 inches high. In favorable weather conditions, the flowers last up to a month. This plant often produces several flowering stems on each rootstock and colonizes easily. However, red trilliums need 15 years to reach flowering size. They are hardy in plant zones 3 through 7.

Other Trilliums

• Nodding trillium (T. cernuum) stems curve downward so that the pink or white flower is below the leaves. Prairie trilliums (T. recurvatum) have brownish-purple flowers and are hardy in zones 4 though 9. They have silver-and-green mottled foliage that's even more attractive than the flowers. The lovely painted trilliums (P. undulatum) have white flowers with rose-red throats. They grow best in cold, upland climates, such as the Upper Midwest and higher elevations in the Appalachians.