by Matt Gibson
The nodding onion is a unique flowering plant native to Canada, North America, and Mexico. This plant’s exotic-looking flowers and its easygoing personality that allows it to adapt to almost any conditions have made it a popular plant among gardeners. It’s easy to see why the nodding onion is a favorite. A ball of star-shaped flowers forms atop each drooping stem. The downward-leaning stems give the plant the “nodding” look referred to in its title, but the tendency to droop downward actually serves a practical purpose for the nodding onion as well—nodding on their stems lets the nodding onion to protect the nectar inside each bloom from the rain.
Native American tribes used the nodding onion plant as a medicine, with traditional use relying on the bulbs of the plant to treat croup, colic, colds, and fevers. The medicinal properties of nodding onion are similar to the healing properties of garlic. The nodding onion plant is closely related to the autumn wild onion, but the two varieties differ in the type of flower cluster each plant develops as well as the fact that unlike the autumn wild onion, the nodding onion is prone to early flowering.
The leaves, bulbs, and bulblets of the nodding onion plant were sometimes eaten by the First Nations who are indigenous to the northwest coast of the United States. The nodding onion’s flowers have the benefit of attract an array of butterflies, including the hairstreak butterfly, and butterflies make excellent pollinators. The city of Chicago gets its title from the Algonquin name for the plant, “chigagou,” which means “onion field” and, one imagines, may also have been used to refer to this onion relative and member of the allium family.
The beautiful blooms of the nodding onion are unique in appearance and have a lot to do with this plant’s popularity in modern cultivated gardens. Each nodding onion plant features pink- to purple-tinted droplet-shaped flower clusters that sit atop two-foot drooping stems, which are adorned with blue-green foliage. The flowers are known to attract butterflies and hummingbirds. The nodding onion blooms in midsummer and is pollinated by short-tongued bees.
Varieties of Nodding Onion
There are several different cultivars of nodding onion that have become popular among modern gardeners. We’ll discuss those varieties here. They’re the species of nodding onion that you’re most likely to find for sale at your local nursery or garden center or encounter in other gardeners’ yards or in trades with them. Though other varieties of the nodding onion plant certainly exist, you’re less likely to find them in gardening settings.
Once classified as a different species altogether, the nodding onion variety called “Oxy White” is a cultivar that was named for its white blossoms and is slower growing than other varieties. The “Major” cultivar is famous for producing larger plants and flowers than most other varieties (a quality that contributed to its name). The “Leo” variety produces white flowers that are usually tinged with pink, and Leo tends to bloom later in the season than other varieties of nodding onion. The “Hidcote” variety of nodding onion is native to the UK, and this breed is known for the large, rose-purple flowerheads it produces. The Hidcote cultivar was given the Royal Horticultural Society’s Award of Garden Merit. The RHS chooses plants to bestow with this honor as a signal to consumers that the RHS’s experts recommend the plant as a good performer that’s well suited to the conditions of most home gardens.
Growing Conditions for Nodding Onion
The most incredible feature of the nodding onion is its adaptability to different growing conditions. This plant has the special capability of being able to not only grow but to really flourish in just about any environment. However, the nodding onion plant really thrives when it’s provided with full sunlight and relatively dry, well-drained soil. However, nodding onion can tolerate some shade, too, especially when it’s grown in a hot climate. This plant is considered to be hardy in USDA zones 4 through 8.
Nodding onion is versatile and happy anywhere, but it’s really a perfect fit when you’re looking for plants to place in rock gardens, borders, or cottage gardens. It is most effectively positioned in small groups among perennial plants that will hide its declining foliage.
How to Plant Nodding Onion
Nodding onion is available to plant from both seeds and plugs, and both options are usually available at nurseries and garden centers. Sow seeds in containers during the spring, and transplant outdoors after danger of the last frost has passed in your area. Or you can choose to sow seeds directly into the ground outdoors, which will allow the seed coat to crack as a result of the shifting winter temperatures.
Of course, this stratification process can be mimicked indoors if you desire and as long as you plan ahead. To stratify seeds indoors, simply place the seeds onto a moistened folded paper towel inside of a plastic resealable baggie, seal it, then put them into the refrigerator for 60 days. After the 60 days have passed, then place the baggie in a warm location, and the seeds inside should split. Harden off the seedlings, and place them outdoors after all danger of the last frost has passed in your location and the soil is workable.
Care for Nodding Onion
This member of the allium family has the same care instructions and precautions as others of its kind. The nodding onion will self seed with ease and at high volume. You can avoid this (if you want to reduce unwanted spreading) by deadheading the plant’s spent flowers. Collect nodding onion seeds when the capsules are tan or straw-colored and the seeds are black, then store them in the refrigerator. Nodding onion seeds stored this way will stay active for up to three years. Divide your plants every third year—or whenever you’re working with a nodding onion plant and notice that eight to 10 bulbs appear in its clump.
Garden Pests and Diseases of Nodding Onion
Nodding onion is generally a crop gardeners can cultivate without worrying too much about pests and disease. However, it can be susceptible to bulb rot in overly damp conditions and is sometimes plagued by onion flies and thrips. There are a few fungal diseases that affect members of the onion family, and therefore nodding onions, as well. Some wildlife that pass through your yard, such as bears and squirrels, may eat the bulbs. Deer and elk may graze on new spring growth, but they will not eat the flowers of your nodding onion plants, as they are deer-resistant.
Companion Planting With Nodding Onion
Nodding onion tends to see deterioration in its foliage during the hot summer months, especially in areas susceptible to heat. For this reason, it’s best to plant your nodding onions in groups among other hot-tempered perennials so they can keep the allium’s discolored foliage covered with their freshly sprouted green vegetation.
Nodding onion grows wonderfully alongside wild geranium and other low-lying groundcovers. This plant is also a perfect companion to compact varieties of liatris, such as the “Kobold” variety, especially when the nodding onion is positioned directly in front of the liatris plants. Winecup blossoms will look especially neat rambling around the nodding onion bulbs.
Harvesting Nodding Onion
Nodding onion leaves can be gathered during the spring and fall. Harvest this plant’s bulbs during the second year, when they are large enough to be used in the same way you would an onion. Flower stem bulblets can be harvested during the summer. Use these in the kitchen just like you would storebought onions—sauteed and included in your dishes as a seasoning or added as a raw ingredient in salads or wraps. You can use the onions raw, or you can saute them, boil them, or pickle them depending on what you’re preparing. You can dry any extra bulbs your plants produce to use later as a seasoning.
Want to Learn More About Nodding Onion?
Check out this tutorial to learn how to properly separate nodding onion plants:
Watch this short video to learn five interesting facts about the nodding onion plant:
This informative session with a professor of horticulture at University of Minnesota highlights the wild nodding onion:
Check out this short video to see the nodding onion plant in full bloom in an Iowa nursery:
Don’t miss these helpful resources on nodding onion to learn more.
Fine Gardening covers Nodding onion
Illinois Wildflowers covers Nodding Onion Allium cernuum
Missouri Botanical Garden covers Allium cernuum
Prairie Moon Nursery covers Nodding Onion
Royal Horticultural Society covers Plants that Preform
Lady Bird Johnson Wildflower Center covers Allium cernuum