Whether it’s referred to as nodding onion, sweet onion, or lady’s leek, there’s no mistaking the clusters of pink to lilac flowers that hang like baubles on this species of Allium. Sturdy, cylindrical stems that rise from attractive clusters of grass-like leaves seem fully capable of supporting the encased blooms growing at their tips; that is, until an umbel of pinkish flowers spills out of its gauzy sheath, causing the stem to unexpectedly curve and tip the flower-laden umbel upside down.
Nodding onion is a hardy perennial bulb that prefers moist, well-drained soils, but it also thrives in a wide range of soils, from rocky to clay. It has a wide distribution throughout the United States and is often found near streams and in sunny, open areas. It prefers full or part sun and attracts hummingbirds, butterflies, and bees during its mid-summer bloom season. Gathering nectar and pollen while hanging upside down is not appealing to many insects, but it’s not a deterrent to bees. The nodding habit (cernuum means “nodding” in Latin) of the plant also helps to protect the nectar from the rain. After the flowers fade, decorative seed heads with spherical fruits split open to release black seeds. Nodding onion can spread by reseeding, but it takes years to develop into a flowering plant. More often, the bulbs produce new offsets. It’s very tolerant of drought once established and of proximity to black walnut trees. Whether massed, grown in a small grouping, or interplanted with other perennials, nodding onion’s short height and sturdy-yet-delicate form is versatile enough for both formal and informal gardens. It does double duty in vegetable gardens because the mildly onion-scented leaves that are so tasty to humans are a repellent for many garden pests.
Native habitats include dry to moist prairies, stream banks, rocky soils in glades, and open woods. Suitable for a variety of sites, from native or cottage gardens to meadows to borders or formal gardens. Best planted in small groups and interplanted with other perennials to hide withering foliage in late summer. Plants benefit from being divided every third year or when 8 to 10 bulbs appear in a clump.
Plant Characteristics:
Grows 8-18” tall.
Prefers full or part sun.
Thrives in rocky soils and grows in a range of well-drained soils. Tolerates drought.
Nodding umbels of flowers are 1 ½-2” wide, consisting of 40-60 flowers. For 3-4 weeks June-August, umbels emerge from a pair of pinkish-white, sack-like membranes. Each flower consists of 6 lanceolate-shaped tepals, long white filaments, and yellow anthers and hangs from a green or reddish, ½-1” pedicel. Seed capsules follow with several small black seeds.
One or more cylindrical stalks emerge from a tuft of solid-and-flattened green basal leaves up to 12” long. Green or reddish-purple stalks are up to 1-1/2’ long and mostly erect.
A long bulb produces clonal offsets to form new bulbs underground.
Wildlife Value:
Host plant for larvae of hairstreak butterflies. Nectar and pollen attract hummingbirds; butterflies; and honey, bumble, and sweat bees. Squirrels eat the bulbs and deer graze the early-spring foliage.
Medicinal, Edible, and Other Uses:
The juice of the plant is used to treat colds, croup, kidney stones, and sore throats. A poultice is applied on the chest to treat respiratory ailments.
The bulbs, young leaves, and flowers are all edible, either raw or cooked, and have a strong onion flavor that some consider to be more complex than that of chives. Use the leaves and blossoms in salads and to season soups and other dishes. Gather leaves during spring and fall, and gather bulbs in their second year when they are larger.