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Ornamental Onion Allium hollandicum

Phonetic Spelling
AL-ee-um hol-LAN-dih-kum
Description

Allium hollandicum, commonly referred to as ornamental onion, is a bulbous perennial characterized by its showy violet flowers. The flowers bloom from May to June and attract butterflies. 

This low maintenance accent plant is best grown in moist to dry soils in full sun to partial shade. Plant in fall to add color to a mixed border, cottage garden, or butterfly garden.

Pests, Insects, and Other Plant Problems: Overly damp conditions leave ornamental onions prone to fungal issues, including bulb rot, rust, and mildew. Leaf spots and thrips are also common threats to ornamental onions. 

 

VIDEO Created by Elisabeth Meyer for "Edibles, Bulbs, and Houseplants" a plant identification course offered in partnership with Longwood Gardens.   

Profile Video:
See this plant in the following landscape:
Cultivars / Varieties:
  • 'Purple Sensation'
    Most popular cultivar today. Inexpensive and dependable, typically returns every year. Violet flowers. 2'-3' tall. Mid-late May.
'Purple Sensation'
Tags:
#purple#herbaceous perennial#sun tolerant#wildlife#spring flowering bulbs#loamy soil#sun#flower#perennial#sunshine#dry soil#summer flowers#sandy soil#part shade#bulb#easy to grow#low maintenance#cottage garden#cottage#full sun#showy#cutting garden#perennial flowers#full sun flowers#division#easy care#purple flowers#pollinators#herbaceous#wildlife plants#accent#dry soils tolerant#perennial bulb#dried arrangements#colorful#flowering#border#violet flowers#pollinator plant#accent plant#small plant#moist#deer resistant#cut flowers#pollinator garden#loamy soils tolerant#loam#flowers#butterfly friendly#sandy soils tolerant#mass planting#rabbit resistant#spring interest#flower arrangements#small group#violet#drought tolerant#partial shade#showy flowers#wildlife plant#moist soil#full sunlight#attractive foliage#summer interest#borders#perennials#butterflies#dried flowers#spring flowers
 
Cultivars / Varieties:
  • 'Purple Sensation'
    Most popular cultivar today. Inexpensive and dependable, typically returns every year. Violet flowers. 2'-3' tall. Mid-late May.
'Purple Sensation'
Tags:
#purple#herbaceous perennial#sun tolerant#wildlife#spring flowering bulbs#loamy soil#sun#flower#perennial#sunshine#dry soil#summer flowers#sandy soil#part shade#bulb#easy to grow#low maintenance#cottage garden#cottage#full sun#showy#cutting garden#perennial flowers#full sun flowers#division#easy care#purple flowers#pollinators#herbaceous#wildlife plants#accent#dry soils tolerant#perennial bulb#dried arrangements#colorful#flowering#border#violet flowers#pollinator plant#accent plant#small plant#moist#deer resistant#cut flowers#pollinator garden#loamy soils tolerant#loam#flowers#butterfly friendly#sandy soils tolerant#mass planting#rabbit resistant#spring interest#flower arrangements#small group#violet#drought tolerant#partial shade#showy flowers#wildlife plant#moist soil#full sunlight#attractive foliage#summer interest#borders#perennials#butterflies#dried flowers#spring flowers
  • Attributes:
    Genus:
    Allium
    Species:
    hollandicum
    Family:
    Amaryllidaceae
    Life Cycle:
    Bulb
    Recommended Propagation Strategy:
    Division
    Wildlife Value:
    Flowers attract butterflies.
    Play Value:
    Attractive Flowers
    Colorful
    Easy to Grow
    Wildlife Food Source
    Dimensions:
    Height: 2 ft. 0 in. - 2 ft. 6 in.
    Width: 0 ft. 6 in. - 0 ft. 9 in.
  • Whole Plant Traits:
    Plant Type:
    Bulb
    Herbaceous Perennial
    Perennial
    Maintenance:
    Low
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Loam (Silt)
    Sand
    Soil Drainage:
    Moist
    Occasionally Dry
    USDA Plant Hardiness Zone:
    4a, 4b, 5b, 5a, 6b, 6a, 7b, 7a, 8a, 8b, 9b, 9a
  • Fruit:
    Fruit Type:
    Capsule
  • Flowers:
    Flower Color:
    Purple/Lavender
    Flower Inflorescence:
    Umbel
    Flower Value To Gardener:
    Good Cut
    Good Dried
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Petals:
    6 petals/rays
    Flower Description:
    The showy violet flowers bloom from May to June.
  • Leaves:
    Leaf Color:
    Green
    Leaf Type:
    Simple
    Leaf Arrangement:
    Rosulate
    Leaf Shape:
    Linear
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    < 1 inch
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Naturalized Area
    Landscape Theme:
    Butterfly Garden
    Cottage Garden
    Cutting Garden
    Drought Tolerant Garden
    Pollinator Garden
    Design Feature:
    Accent
    Border
    Mass Planting
    Attracts:
    Butterflies
    Resistance To Challenges:
    Deer
    Drought
    Dry Soil
    Rabbits