White Rosenbachian Allium Allium rosenbachianum 'Album'

👤 Non-toxic to humans
🐾 Toxic to pets
🌸 Blooming
🍪 Edible
‍🌱 Easy-care
allium 'Album'


Allium rosenbachianum 'Album', commonly known as ornamental onion, is a striking and elegant perennial plant. It is characterized by its beautiful round, globe-like flower heads that consist of tightly clustered star-shaped flowers. The blooms are a pristine white color, which contrasts dramatically against the green foliage. The leaves of the ornamental onion are strap-shaped, creating a lush, basal cluster that accents the stems and blooms above. The foliage is a bright, glossy green that remains attractive even when the flowers are not in bloom. This provides a pleasing backdrop for the stunning white flower spheres. As the plant matures, these flower heads emerge atop sturdy, upright stems which rise above the foliage, imparting an airy and sophisticated look in the garden setting. The blossoms can create a dazzling display when they catch the sunlight, making them a popular choice for gardeners looking to add a touch of elegance to their landscaping. Ornamental onions are also known for their delightful fragrance, which can be quite pronounced and can attract bees, butterflies, and other pollinators to the garden. Once the blooming period is over, the seed heads of the Allium rosenbachianum 'Album' can still provide visual interest, as they dry to a beige or tan color, maintaining their globular shape on the stems. These seed heads can be left in place to add winter interest to the garden or cut for use in floral arrangements. Overall, the appearance of Allium rosenbachianum 'Album' is one of restrained beauty, with its crisp white blossoms and lush green leaves creating a classic and sophisticated presence in the landscape.

Plant Info
Common Problems

About this plant

  • memoNames

    • Family


    • Synonyms

      Rosenbach's Allium, White Giant Allium

    • Common names

      Allium rosenbachianum 'Album'.

  • skullToxicity

    • To humans

      The Allium rosenbachianum 'Album', commonly known as ornamental onion, is not generally considered toxic to humans. There is no significant toxicity associated with the ingestion of this plant, and handling it typically doesn't cause any adverse reactions. Most allium species are edible or at least non-toxic to humans; however, they may cause discomfort if consumed in large quantities due to their strong flavor and potential irritants.

    • To pets

      Ornamental onion is toxic to pets, including cats and dogs. Allium species contain compounds that can be harmful to animals if ingested. The toxicity manifests as oxidative damage to red blood cells, leading to symptoms such as vomiting, diarrhea, abdominal pain, and in severe cases, anemia. If your pet consumes any part of an ornamental onion, it is essential to seek veterinary care immediately, as the consequences can be serious, particularly if left untreated.

  • infoCharacteristics

    • Life cycle


    • Foliage type


    • Color of leaves


    • Flower color


    • Height

      2-3 feet (60-90 cm)

    • Spread

      1 foot (30 cm)

    • Plant type


    • Hardiness zones


    • Native area

      Central Asia


  • money-bagGeneral Benefits

    • Ornamental Value: Allium rosenbachianum 'Album', also known as Persian Onion, adds an aesthetic appeal to gardens with its large, showy white flowers.
    • Pollinator Attraction: It draws in bees, butterflies, and other pollinators, which are essential for the fertilization of many plants.
    • Low Maintenance: Persian Onion is known for being drought-tolerant and requiring minimal care once established.
    • Drought Tolerance: Its ability to withstand dry conditions makes it suitable for xeriscaping and water-wise gardens.
    • Deer and Rodent Resistance: The plant is resistant to browsing by deer and damage by rodents, protecting it from garden pests.
    • Long Blooming Period: The plant has a prolonged flowering period, which can provide visual interest in the garden throughout the season.
    • Companion Planting: It can be successfully combined with other perennials to create visually appealing and diverse garden designs.
    • Cut Flowers: The blooms of the Persian Onion hold up well in floral arrangements, bringing garden beauty indoors.

  • medicalMedical Properties

    This plant is not used for medical purposes.

  • windAir-purifying Qualities

    This plant is not specifically known for air purifying qualities.

  • leavesOther Uses

    • Allium rosenbachianum 'Album', commonly known as Giant Allium, can be used in floral arrangements due to its large, eye-catching white flowers that add height and drama to bouquets.
    • The dried seed heads of the Giant Allium can be spray painted and used in arts and crafts to create unique decorations and ornamental displays.
    • The sturdy stems of the Giant Allium can be utilized as natural supports for smaller, more delicate plants in the garden.
    • The plant can serve as a teaching tool in botany and horticulture classes, illustrating bulb development and flowering plant life cycles.
    • Giant Allium can be planted as a natural pest deterrent in gardens, as its strong scent is believed to repel certain insects and rodents.
    • Photographers and artists may use the striking appearance of the Giant Allium as a subject in their work to explore themes of nature and beauty.
    • In ecological landscaping, the Giant Allium can be used as part of a biodiversity strategy to attract pollinators like bees and butterflies.
    • This plant can be used in landscape design to create a vertical element in rock gardens, borders, or as an architectural feature in modern gardens.
    • The Giant Allium's unique globular flower shape can inspire design elements in fields such as architecture, interior design, and fashion.
    • Gardening enthusiasts might use the propagation of Giant Allium as a way to practice bulb division and improve their gardening skills.

Interesting Facts

  • bedFeng Shui

    The plant Allium Giganteum is not used in Feng Shui practice.

  • aquariusZodiac Sign Compitability

    The plant Allium Giganteum is not used in astrology practice.

  • spiralPlant Symbolism

    • Purity: The 'Album' in Allium rosenbachianum 'Album' denotes white, symbolizing cleanliness and innocence.
    • Unity: Alliums are often seen as a symbol of unity due to their globe-shaped clusters of flowers which suggest togetherness.
    • Patience: The allium takes time to bloom and thus can represent patience and the reward of waiting for something beautiful.
    • Prosperity: In some cultures, alliums are thought to bring luck and are symbols of abundance and prosperity.
    • Strength and Courage: Given their hardy nature and strong stems, they are also seen as emblems of strength and courage.
    • Protection: Historically, alliums have been used to ward off evil spirits and bad luck, so they are associated with protective qualities.

Every 1-2 weeks
2500 - 10000 Lux
Every 2-3 years
Not needed
  • water dropWater

    The Regal Onion should be watered sparingly as it prefers well-drained soil and can be susceptible to rot if overwatered. During the growing season, water the plant when the top inch of soil feels dry, which may be roughly once a week, depending on climate conditions. Provide approximately 1 gallon of water to saturate the soil around the plant. Decrease watering frequency after the blooms have faded and the leaves begin to yellow, signaling the plant is entering dormancy. It's important not to let the soil become completely dry for prolonged periods.

  • sunLight

    The Regal Onion thrives in full sunlight, making a sunny spot in the garden or landscape its ideal location. Position the plant where it will receive at least six hours of direct sunlight every day. These conditions will ensure the strongest growth and best flowering results for this ornamental onion.

  • thermometerTemperature

    The Regal Onion grows best in temperatures between 50°F and 80°F and can tolerate a range from just around freezing to 90°F. For optimal growth, avoid exposure to temperatures below 28°F or above 90°F, which can stress the plant or cause damage.

  • scissorsPruning

    Pruning the Regal Onion isn't typically necessary but removing spent flower stalks after blooming can encourage better bulb development for the next year. Dead or damaged foliage should be removed to maintain plant health. The best time for pruning is after flowering, in late summer, when the foliage begins to decline naturally.

  • broomCleaning

    As needed

  • bambooSoil

    White Ornamental Onion prefers well-drained soil with a pH range from 6.0 to 8.0. A mix containing equal parts of garden soil, compost, and sharp sand or perlite would be ideal to promote good drainage and provide nutrients.

  • plantRepotting

    White Ornamental Onion bulbs should be replanted every three to four years to prevent overcrowding and renew soil nutrients. Bulbs should be lifted, divided, and replanted in the fall.

  • water dropsHumidity & Misting

    White Ornamental Onion is not particularly humidity-sensitive but thrives best in outdoor environments where the humidity is natural and not controlled.

  • pinSuitable locations

    • Indoor

      Ensure bright light, cool temps, and good air flow.

    • Outdoor

      Plant in full sun, well-drained soil, autumn or spring.

    • Hardiness zone

      4-9 USDA

  • circleLife cycle

    Allium rosenbachianum 'Album', commonly known as Ornamental Onion, begins its life cycle as a dormant bulb planted in late summer to autumn. Once planted, the bulbs undergo root development and cold stratification during the winter months. Come spring, the bulb sends up a shoot, which will develop into a sturdy stem bearing the plant’s distinctive white spherical flower clusters. After flowering in late spring to early summer, the plant sets seed, which can be dispersed by wind or captured for cultivation. Once the flowering and seed-setting stages are complete, the foliage dies back and the plant enters a dormant period during the hotter months. The cycle repeats itself yearly, with bulbs either being left in place to naturalize or being dug up and divided to spread or prevent overcrowding.

  • sproutPropogation

    • Propogation time


    • Allium rosenbachianum 'Album', commonly known as white giant allium, is typically propagated through division of the bulbs. The optimal time for this process is in the fall, after the leaves have died back but before the ground freezes. A mature bulb can be gently dug up and the smaller bulblets that have formed attached to the parent bulb can be separated. Each bulblet should have a portion of the basal plate to ensure a new plant will grow. The separated bulblets can then be planted immediately in well-draining soil, around three times their width apart, and at a depth of around two to four inches (5 to 10 centimeters) depending on their size. This method allows gardeners to clone their plants effectively, maintaining the exact traits of the parent plant with each new bulb.