How to Plant, Grow, and Care for Nodding Onion Plants

Onions are tasty, but they are also beautiful plants with many ornamental attributes in the landscape. Nodding onions are particularly special for their pendulous pink flowers that “nod” over when they bloom. These attract native bees and pollinators to the site. 

Growing nodding onions is easy if they have the right setting. Simply scatter some seeds in spring or transplant bulbs into the ground. By summer, your perennials should be blooming easily!

Because it grows in most regions of the U.S., this native easily adapts to garden conditions with adequate care. Learn all the best tips and tricks to grow healthy, bodacious nodding onion plants. 

What Is Nodding Onion?

The nodding onion is a perennial native to North America, and it is part of the onion family Allium. The species’ entire scientific name is Allium cernuum. This name properly identifies such plants at nurseries. 

This onion belongs to the Amaryllidaceae family, like garlic, chives, and sweet onions. This species grows in meadows, dry open forests, rocky lands, and sandy soils. Although considered a wet meadow onion rather than a dry habitat one, nodding onion is drought tolerant once established and thrives in well-draining soil.

Like all other alliums, nodding onions scatter their seeds after successful pollination. They also spread vegetatively through bulbs underground. These small bulbs grow large over time and form scattered colonies of nodding onion. 

History

As most edible native plants do, nodding onions have a rich history of usage and propagation in the United States. On the West Coast, groups like the Squamish and Nuxalk ate the bulbs as delicacies. They’d spot plants growing early in spring, then wait until they’ve died back and put their energy into the bulbs for a substantial harvest. 

Lewis and Clark encountered nodding onions on their travels and noted that the bulbs provided stomach relief from other harder-to-digest plants like camas bulbs. Since their travels, this plant has continuously spread across America. Nowadays, plant nurseries propagate it and help further its growth. 

Native Area

Allium cernuum is native to wide swaths of the U.S., from New York to Washington and south to Georgia and Arizona. Plants readily adapt to variable conditions and perform well in most areas. They naturally thrive in grassy fields, open forests, and sandy areas. In the Pacific Northwest, they favor the coastal bluffs with their loose soil and ocean sea spray.

This perennial bulb grows in zones four through eight. The plant’s wide range causes slight variations in its growth, flowering habit, and color. Select seeds from local cultivars or nurseries so that they better adapt to your region’s climate. 

Characteristics

Nodding onions are attractive little plants, and one cultivar, ‘Hidcote’, has even received the Royal Horticulture Society Award of Garden Merit. Species plants grown in the U.S. have varying attributes, although all share nodding clusters of flowers and flat, long foliage. 

During flowering, the leaves stay grayish-green and create a spectacular contrast with the bright blooms. After flowering in fall, the plants suck up all the nutrients from the foliage and swell their bulbs. They then create smaller bulbs beneath the soil over the winter and prepare to sprout anew in spring.

Uses

I grow yellow onions and chives for eating and have a few ornamental onions in my garden. Although ornamental kinds like nodding onions are edible, I prefer to let them flower and complete their life cycle. That way, they produce seeds and continue thriving as a native species.

Don’t let me discourage you from growing your own nodding onions to eat! They are a delicacy when cooked for a long time, and they grow sweet and flavorful with oil, salt, and pepper. Just be sure not to eat wild plants–you’ll avoid accidentally ingesting a poisonous lookalike, and you’ll let the species continue thriving in nature. 

This flowering plant shines when planted en masse, and when used as an accent plant in rock gardens and borders. It is also a star in grassland habitats and open forested areas. It surprisingly tolerates growing beneath black walnut trees and is a useful ground cover in gardens with these trees. 

Where To Buy Nodding Onion

Want to get your hands on some nodding onion plants? There are three ways you’ll find this plant, seeds, bulbs, or potted plants. 

You can find seeds at native seed retailers or on plants in your local area. Seeds are usually ripe on their stalks from late summer to fall. When collecting seeds, leave more than three-fourths of them so that the plant still has some to propagate itself. 

Bulbs and potted nodding onion plants are available online and at local native plant nurseries. Sometimes commercial nurseries carry this plant, although it is rarer than your average daffodil and a bit harder to find. The hard work searching for this plant pays off, as its blooms will have your neighbors asking, “What’s that pretty flower?”

Planting

Nodding onions grow their best in sunny spots with well-drained soil. Plant seeds in fall in areas that have winters below 40°F (4°C) for two to three months. They require cold stratification to germinate.

In mild winter zones, start in fall and keep seeds in the refrigerator for two months or longer. In early spring, take them out and plant ⅛ inches deep in propagation trays outside. Keep the soil moist, and the seeds should germinate within six weeks.

When planting bulbs, ensure there is at least two to three inches of soil covering them. Bulbing plants reside below the soil and gain extra protection from the elements. Don’t worry about burying bulbs too deep, as this kind knows how to reach the light! 

A wet meadow plant, this native performs best with native grasses, perennial wildflowers, and flowering shrubs. Full sun, free-draining soil, and regular water keep it happy throughout the spring and summer. 

How to Grow

Why grow nodding onions? They are well worth the investment. They’ll reward you year after year with pinkish little blooms that slowly pop up throughout your garden. Give your plants a bit of sun and some good soil, and they’ll grow with ease each year.

Light

This ornamental onion needs full sun and an open location to grow abundant flowers. It thrives with six to eight hours of sunlight a day and tolerates more sun with additional moisture. Ensure that taller perennials and shrubs won’t overshadow it. 

In areas with hot, dry summers, situate plants in a location where they’ll have full sun to partial shade. Open, deciduous trees offer the perfect conditions for nodding onions in warm summer areas. If you lack shade, additional moisture also helps plants survive droughts unscathed.

Water

Unlike dry habitat onions, nodding onions are a wet meadow type. They are drought tolerant but prefer consistent moisture, especially during the spring and summer growing seasons. Aim to keep your plants moist but not soggy, and arrange them with other wet-loving perennials and annuals in sunny parts of the garden. 

During the winter months, plants go dormant and require less water than they do in summer. If your garden is already wet and rainy like it is in the PNW, you won’t need to water when the soil is wet. In snowy areas, the snow cover provides sufficient protection and moisture for the bulbs. 

In dry winter areas without snow, ensure your bulbs stay moist throughout the winter. Use the finger test to see if the soil around them is dry or wet. If dry, water. Avoid watering too much in winter, as the plant is not actively growing above ground. 

Soil

Although adaptable, this U.S. native appreciates well-drained fertile soil. It tolerates clay soil so long as it doesn’t receive too much water in winter. Add compost to the soil at planting and every year in fall to provide beneficial humus and nutrients over time. 

These bulbing plants prefer neutral soil pH levels and grow from mildly acidic to mildly alkaline soils. Soil pH is rarely an issue with this native.

Temperature and Humidity

Nodding onions like cold winters and warm summers. They grow without issue in zones four through eight and outside of these zones with a little extra care. In areas without winter chill, this species struggles to grow, but in colder zones, they may come back each spring when protected.

Once your plants die back in fall, cover them with compost or mulch. This keeps the bulbs warm and cozy while frost and freeze abound aboveground. 

This native grows in a range of humidities but thrives where humidity is abundant. Water plants during dry spells in summer when their soil is dry. This should provide adequate humidity for your onion.

Fertilizing

Established plants generally do not need fertilizer. They are a no-fuss species with low nutrient requirements. In poor-nutrient soils, adding compost at planting and every year thereafter should provide abundant nutrients for your ornamental onions. 

If you know your soil is lacking nutrients, add the recommended amount of all-purpose organic fertilizer at planting. This gives your plant a boost so that it eventually forms a network with beneficial soil mycorrhizae and bacteria. 

Maintenance

Nodding onions are headache-free and low-maintenance in the garden. Native plants evolved to grow in our country, and they offer the pretty attributes of ornamental plants with many benefits. One of these benefits is not having to fuss about pruning or managing your plant.

One thing to note is that these onions spread naturally over time. Their seeds scatter in late summer and fall. If you’d like to prevent their spread in your garden, simply harvest the seed pods before they open and scatter the seeds. That way, you’ll enjoy yearly blooms without unwanted spreaders. 

Growing In Containers

Allium plants are excellent container specimens! Like most other bulbing plants, their perennial nature allows for easy care inside pots. Plant bulbs or maturing plants inside decorative, frost-protective containers with drainage holes, and use well-draining soil. Add sand or perlite to humus-rich soil to add drainage and structure.

Container plants are more susceptible to the elements, and a little extra care helps them thrive. In winter, place them under a covered spot where they won’t receive excess rainwater and become soggy. Soggy soil in cold temperatures sometimes leads to root rot, and protection prevents this. 

In summer, ensure your container plants have sufficient moisture. Water them well when the soil dries out, and wait to add more water until it dries out again. Aim for periodic soakings rather than frequent mistings. 

Container plants may also need additional fertilizer as they don’t have access to the plethora of microbes in native soils. Add compost each year to the container, or use the recommended dosage of organic fertilizer and mulch well. 

Propagation

Nodding onions reward you with unlimited plants. Mature bulbs produce offsets that look like mini bulbs. In the fall, after the foliage has died back, dig up the plant and separate the little bulbs. Propagate them in your garden or containers, and give extras to your friends! 

This U.S. native also reproduces through seeds, and these grow new genetic variants of your plant. Let the seeds scatter and plant themselves in the garden, and enjoy new flower colors and slight variations.

If you’d prefer to keep this plant under control, collect the seeds before they fall in late summer. Sow the seeds where you’d like in the fall, and keep the soil moist until they germinate in the spring. 

Common Problems

Although a rare occurrence, nodding onions sometimes experience growing issues. If your plant is struggling to grow, it is most likely experiencing a cultural condition that you can easily fix with the right care. Keep reading and learn how to get your plant back on track.

Lack of Flowers

Nodding onions love the sun and require at least six hours of direct sunlight a day during the growing seasons. When they grow in the shade, they lack the energy required to bloom and produce a few measly blossoms. Fix this issue by transplanting your plant in the fall to a sunny location.

If your plant is growing in Full sun, receives adequate moisture, and still lacks flowers, it may need nutrients. Fertilize with a diluted version of the recommended dosage of organic fertilizer, or add compost and water well. 

Yellow Leaves

Yellow leaves are no sight any gardener wants to see unless it’s autumn, and they’re supposed to be yellow! Yellow leaves on a nodding onion plant may be an issue depending on the time of year. If it’s late summer or fall, then the leaves are yellow naturally and are nothing to worry about. The plant is simply sucking down the nutrients from its foliage into its bulb. 

If your plant has yellow leaves during the growing season, it could indicate too little or too much water. To correct the issue, cut back on irrigation or add more water as needed. 

Pests

Nodding onions are incredibly fragrant and smell like pungent onions when you brush by them. Their presence in the garden wards off most pests with the fragrance.

Pests that do feed on the plant are most likely native ones that like its foliage. Avoid adding pesticide products to natives as it hurts the pollinators who decide to visit the plants. 

Diseases

Practically disease-free, these onions shouldn’t experience any disease or pest issues. Yellow leaves and rangy growth are usually signs of a cultural condition that needs correction, like not enough sun or water.

Frequently Asked Questions