Create Your Garden

Allium unifolium (Oneleaf Onion)

Oneleaf Onion, American Onion, Allium grandisceptrum , Ornamental Onion, Spring Bulbs, Spring Flowers

AGM Award
Allium unifolium, Oneleaf Onion, American Onion, Allium grandisceptrum , Ornamental Onion, Spring Bulbs, Spring Flowers, Pink Flowering Onion, Late Spring Flowers, Early Summer Flowers
Allium unifolium, Oneleaf Onion, American Onion, Allium grandisceptrum , Ornamental Onion, Spring Bulbs, Spring Flowers, Pink Flowering Onion, Late Spring Flowers, Early Summer Flowers

Allium Unifolium (Oneleaf Onion) is a compact perennial with delicate clusters of up to 30 fairly large, star-shaped, satiny, rose-pink flowers. The blossoms are borne atop the foliage of short gray-green basal leaves. Blooming in late spring to early summer, this charming Allium spreads freely in the garden without being a pest.

  • Recipient of the prestigious Award of Garden Merit by the Royal Horticultural Society
  • Grows up to 12-24 in. high (30-60 cm). This Allium naturalizes easily and will slowly spread to form lovely colonies.
  • Easily grown in fertile, dry to medium moisture, well-drained soils in full sun.
  • Stunning in beds and borders, or rock gardens. For best visual impact, plant in groups (at least 20 bulbs).
  • Known for attracting bees, butterflies, and other pollinators, but deer ignore it.
  • To be planted in fall.
  • No serious pest or disease issues. Keep an eye out for onion white rot, and downy mildew.
  • Propagate by seed, sowing seeds in containers with bottom heat when ripe and grow on under glass. Remove offsets in spring and grow on under glass for 2 seasons.
  • Allium Unifolium is native to the coastal mountain ranges of California, Oregon, and Baja California.

Many hundreds of Allium species exist, but only a modest few have made a name for themselves as garden plants. The ornamental onions distinguish themselves by their great diversity in color, inflorescence and flowering height. Many species bloom in early summer – just after the spring-flowering period and just before the exuberant full bloom of summer. All species can be used in the border. Certain small species are just perfect for a rock garden, and several lend themselves to naturalizing.

Learn How To Plant And Care for Your Spring Flower Bulbs


 To achieve optimum flowering results, it is important to plant the bulbs at the right time.

Requirements

Hardiness 4 - 9
Heat Zones 1 - 9
Climate Zones 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Bulbs
Plant Family Amaryllidaceae
Genus Allium
Common names Ornamental Onion, Onion
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early)
Height 1' - 2'
(30cm - 60cm)
Spread 3" - 4"
(8cm - 10cm)
Spacing 2" (5cm)
Depth 4" (10cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Fragrant, Showy
Native Plants United States, Pacific Northwest, California, Oregon
Tolerance Deer, Rabbit
Attracts Bees, Butterflies
Garden Uses Beds And Borders
Garden Styles Gravel and Rock Garden
How Many Plants
Do I Need?
Explore Great Plant Combination Ideas
Allium
Guides with
Allium
Not sure which Allium to pick?
Compare Now

Alternative Plants to Consider

Allium cepa Aggregatum Group (Shallot)
Allium cepa (Onion)
Allium sativum (Garlic)
Allium ‘Pinball Wizard’ (Ornamental Onion)
Allium ‘Purple Rain’ (Ornamental Onion)
Allium amethystinum ‘Red Mohican’ (Ornamental Onion)

Recommended Companion Plants

Allium roseum (Rosy Garlic)
Clematis ‘Blue Angel’ (Late Large-Flowered Clematis)

Find In One of Our Guides or Gardens

Pure White Flowers for a Touch of Elegance in Your Garden
26 Terrific Summer Bulbs to Grow in your Garden or Pots
30 Best Spring Flowers to Spruce up Your Garden
How to Create an Enchanting Butterfly Garden
For the Love of Butterflies: Best Flowers to Attract them to Your Garden
6 Reasons You Should Create a Butterfly Garden
For the Love of Bees: Best Flowers to Attract them to Your Garden
How to Cultivate a Thriving Bee-Friendly Garden
Popular Flower Bulbs For Your Garden and Pots
18 Best Plants That Repel Mosquitoes
Learn How To Plant, Grow and Harvest Chives
Brighten Up Your Garden From January Through May with Colorful Flower Bulbs
Wonderful Plants That Repel Insects
Allium (Ornamental Onion)
Great Rose Companion Plants: Allium
Bulbs that return to the garden year after year!
Tall Alliums for your Garden Borders
Small Allium Species for the Rock Garden
Learn How To Plant And Care for Your Spring Flower Bulbs
Great Bulbs and Perennials as Companion Plants for Azaleas and Rhododendrons
Plants with Purple Flowers to Add Charm to Your Garden
Awesome Allium Combos
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
Buy Plants

Requirements

Hardiness 4 - 9
Heat Zones 1 - 9
Climate Zones 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Bulbs
Plant Family Amaryllidaceae
Genus Allium
Common names Ornamental Onion, Onion
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early)
Height 1' - 2'
(30cm - 60cm)
Spread 3" - 4"
(8cm - 10cm)
Spacing 2" (5cm)
Depth 4" (10cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Fragrant, Showy
Native Plants United States, Pacific Northwest, California, Oregon
Tolerance Deer, Rabbit
Attracts Bees, Butterflies
Garden Uses Beds And Borders
Garden Styles Gravel and Rock Garden
How Many Plants
Do I Need?
Explore Great Plant Combination Ideas
Allium
Guides with
Allium
Not sure which Allium to pick?
Compare Now

Gardening Ideas

Plant Calculator

How many Allium unifolium (Oneleaf Onion) do I need for my garden?

Input your garden space dimensions

Your Shopping List

Plant Quantity
Allium unifolium (Oneleaf Onion) N/A Buy Plants

Please Login to Proceed

You Have Reached The Free Limit, Please Subscribe to Proceed

Subscribe to Gardenia

To create additional collections, you must be a paid member of Gardenia
  • Add as many plants as you wish
  • Create and save up to 25 garden collections
Become a Member

Plant Added Successfully

You have Reached Your Limit

To add more plants, you must be a paid member of our site Become a Member

Update Your Credit
Card Information

Cancel

Create a New Collection

Sign Up to Our Newsletter

    You have been subscribed successfully

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Find your Hardiness Zone

    Find your Heat Zone

    Find your Climate Zone