Where in the OLL?

White turtlehead is found in the Rain Garden and Botanical Garden. It is a late bloomer, with unique and eye-catching flowers that stick around after many other plants have faded. In the Rain Garden, it helps to manage rainwater and filter runoff. It attracts pollinators (especially bumblebees) and is host to the native Baltimore Checkerspot butterfly.

Plant growth form

Turtlehead is an herbaceous perennial, able to survive New England winters thanks to its rhizomes (underground stems which store nutrients.) It grows 1.5-3 feet tall and 1-2 feet wide. The leaves are simple (single leaves, not separated into leaflets,) lanceolate (long, narrow, and pointed at both ends,) and have fine-toothed edges. The species name, glabra, refers to the smooth texture of the stems and leaves. The leaf arrangement is opposite (arranged in pairs along the stem), with each pair of leaves rotated ninety degrees from the one below it to catch as much sunlight as possible.

Flowers, fruits & pollinators

True to their name, the tubular flowers of white turtlehead resemble the head of a turtle. (The genus name, Chelone, refers to a nymph in Greek mythology who was turned into a tortoise as punishment for failing to attend Zeus and Hera’s wedding.) Flowers are white, often tinged with light pink towards the tip. The plant blooms in late summer to early fall for several weeks, and attracts bumblebees and hummingbirds. The flowers are bilaterally symmetrical (they can be split into two identical halves) and are made up of five petals. The upper lip, made up of two fused petals, curves down to resemble a turtle’s beak. The remaining three petals are fused to form the lower lip, which has a white or yellow “beard.” Inside are five fuzzy stamens (which make pollen) and a pistil (which transfers pollen to the ovary and creates ovules that are fertilized to make seeds.) Turtlehead’s flowers grow in spikes, with flowers clustered tightly together and blooming from the bottom of the spike upward. The flowers are perfect (meaning that each individual flower contains all of the components necessary for reproduction.)

Ideal location, conditions & cultural needs

Turtlehead’s natural habitats include wetland margins, swamps, and riverbanks, so its preferred conditions are mucky soils and partial shade, but it is also happy in full sun as long as moisture requirements are met. It thrives in rain gardens, woodland gardens, pond edges, or other wet areas such as near eaves and downspouts. With adequate watering, it will also do well in gardens and is commonly used as a border plant. It prefers rich soils with a neutral pH (pH 7), and will benefit from an application of leaf compost.

Planning & maintenance

Turtlehead spreads slowly by rhizomes (underground stems) and tends to form clumps; it does not require regular trimming, though the stems can be pinched back in spring to encourage a more compact plant. A fully-grown plant has about a 2-foot spread.

Cultivars & propagation

Both Chelone glabra and its “Black Ace” cultivar, which has darker leaves with a blackish hue, are suitable for gardens. Turtlehead is most easily propagated by dividing plants in the spring; it can also be grown from seed, but will take months to germinate. White turtlehead is available locally through Nasami Farm and the Hadley Garden Center (which also offers the “Black Ace” cultivar.)

Pests & pathogens

Turtlehead’s bitter leaves resist deer and other animals. It has no major diseases or pests, but may be affected by mildew in drier soils, or if there is poor air circulation or excessive shade.

Landscape & ecosystem

White turtlehead’s unique flowers contribute autumn color to a landscape. In a rain garden or other poorly-drained area, the plant provides natural runoff filtration and management and prevents erosion. It is a food source for bumblebees, hummingbirds, and butterflies, and acts as a host for the larvae of the native Baltimore Checkerspot butterfly (Euphydryas phaeton.)

Human uses

White turtlehead was used for a range of applications—as a contraceptive, a deworming agent, a dietary aid, and a fever treatment—by Native American tribes. Shoots and leaves were also consumed as food in some cases. Its only modern use is in natural medicine as a tonic for digestion and stimulating appetite or as an anti-inflammatory salve, and there has been little scientific investigation on its effects.