All About Alliums: How to Grow and Care for Allium Plants

Allium flowers, also known as flowering onions or ornamental onions, are a part of the *Allium* genus. Alliums include ornamental flowers and culinary herbs, like chives, garlic, shallots, onions, and leeks. Allium flowers are unique for their flowering blooms, which grow atop thin, tall stems in tight spheres known as umbels. These round flower clusters grow in various colors, including pink, lilac, blue, and white. Their vibrant blooms are great for any garden design, and their tall, thin stems make for beautiful cut flowers. Common culinary herbs in the allium family include chives, garlic, shallots, onions, and leeks. 1. __Garlic (*Allium sativum*)__: [Garlic](https://www.masterclass.com/articles/how-to-grow-and-harvest-garlic) is a plant within the allium family that is great to grow in a kitchen garden. A perennial flower, garlic grows from a flower bulb and produces pink flowers from late summer to early fall. You can use garlic as a versatile seasoning to flavor meat, fish, or pasta. 2. __Shallots (*Allium ascalonicum*)__: [Shallots](https://www.masterclass.com/articles/what-is-a-shallot) are also alliums you can add to a kitchen garden. Shallots have a sweeter flavor than most onions, and they’re useful to season a dish or brighten a vinaigrette. Shallots grow from bulbs and bloom during the summer. 3. __Chives (*Allium schoenoprasum*)__: With a subtle oniony flavor, [chives](https://www.masterclass.com/articles/how-to-grow-and-harvest-chives-in-your-garden) have become one of the most widely used garnishes in the world and can be found in most grocery stores and farmer’s markets. Chive plants also produce edible purple flowers known as chive blossoms, which are typically trimmed during harvest. 4. __Onions (*Allium cepa*)__: There are many [onion](https://www.masterclass.com/articles/how-to-grow-onions-at-home) varieties, from sweet onions to red onions and yellow onions, whose hardiness can withstand cool temperature planting and growing. Onion plants are simple to grow and provide a number of benefits through companion planting, giving your flora and vegetable garden all-natural, organic defenses against pests and other detrimental effects. 5. __Leeks (*Allium porrum*)__: [Leeks](https://www.masterclass.com/articles/how-to-grow-leeks) are an edible plant used in many different cuisines. Closely related to onions, garlic, and scallions, the edible parts of leeks are the tightly bound leaf sheaths that form stalk-like bases, which transition into flat leaves. There are different types of ornamental alliums, each with distinct looks. The bloom period and height vary with the kind of allium. Types of allium flowers include: 1. __Tumbleweed onion__: This variety of allium blooms light purple flowers in late spring. Tumbleweed onion is a hardy, drought-tolerant plant. When the seed heads dry and fall, they tumble in the wind, giving this variety of allium its common name. 2. __'Globemaster'__: One of the tallest varieties of allium, ‘Globemaster’ is an ornamental onion that can grow up to three feet tall. Its flower blooms grow in dense clusters, creating eye-catching purple flower heads. This variety of allium blooms in late spring and is a great addition to a rock garden or lawn. 3. __'Purple Sensation'__: Like 'Globemaster,' the allium 'Purple Sensation' is an ornamental onion. With a long bloom time, this variety produces bright purple flowers from late spring to early fall that are rabbit and deer-resistant. 4. __'Star of Persia__: Known for its pale lavender flower heads, this variety of allium is native to ancient Persia—what is now Central Asia. Each flower head has up to 100 individual florets clustered together, and these blooms attract butterflies. 5. __'Mount Everest'__: One of the taller ornamental varieties, allium 'Mount Everest' matures at the height of three feet. Its white flowers make it a great addition to any garden. This variety of the allium plant is also rabbit- and deer-resistant. 6. __Nigrum__: Similar to ‘Mt. Everest,’ Nigrim is a tall variety of allium, making it an excellent cut flower. The white bulbs produce tiny flower clusters with six-petal florets. As a pollinator, nigrum attracts bees and butterflies to a garden. 7. __'Blue of the Heavens'__: With its striking blue blooms, 'Blue of the Heavens' is a colorful allium cultivar. Each flower head has thirty to fifty blooms clustered together, creating dense cut flowers. This variety of allium grows between one and two feet tall. 8. __'Gladiator'__: 'Gladiator' allium is known for its height and colorful bloom. Standing at four feet tall, this variety of allium showcases deep purple flower clusters. Plant this allium variety in clusters to create a vibrant edging along a walkway or garden border. Allium flowers are simple to grow—simply find a sunny spot, and plant your bulbs. Follow these steps to add alliums to your garden: 1. __Choose a site__. Alliums grow best in full sun; however, they can also grow in partial shade. Choose an area that is away from the wind. While the sturdy stems will hold the blooms in place, the flower blooms are delicate and can fall apart from a strong breeze. 2. __Prepare the site__. Plant allium bulbs in the fall for spring blooms. Using a garden till or your hands, dig a hole that is twice the diameter of your bulbs. Place the bulbs eight to twelve inches apart, depending on how close you want your flower clusters to bloom. 3. __Plant the alliums__. Using two hands, place the allium bulb in the hole. Cover the bulb with soil and organic matter. 4. __Add companion plants__. To create a colorful flower border, you can plant alliums with other spring blooms, such as peonies, daffodils, crocus, or tulips. When planted in the right conditions, alliums require minimal maintenance. Consider the following care tips: - __Soil__: Alliums grow best in slightly acidic soils with a [pH level](https://www.masterclass.com/articles/essential-guide-to-soil-ph-guide) between 5.5 and 6.5. Adding organic matter to your soil can help lower the pH level. It’s also essential for the ground to be well-draining: Organic matter can help absorb excess water and prevent your alliums from rotting. - __Water__: Alliums are drought-tolerant. Water your alliums once a week in the morning so the plants can dry in the sun. - __Deadheading__: You can cut the stems to remove the flower clusters for arrangements. However, it’s also important to [deadhead](https://www.masterclass.com/articles/how-to-deadhead-flowers-in-your-garden) the flowers at the end of their bloom time. The leaves will naturally fall to prepare for next season’s blooms. Alliums are toxic to cats and dogs. Keep pets away from your allium flowers as well as edible alliums, such as chives, garlic, onions, and leeks. Alliums contain organic sulfur compounds that become toxic oxidants when ingested by cats and dogs. These highly reactive oxidants can damage your pets’ red blood cells, preventing the spread of oxygen throughout the body. Grow your own garden with Ron Finley, the self-described "Gangster Gardener." Get the [MasterClass Annual Membership](https://www.masterclass.com/) and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community - and the world - a better place. Add light blue alliums to your lawn for a pop of color, or grow garlic in your kitchen garden to use as a classic seasoning.