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Euphorbia milii

Phonetic Spelling
yoo-FOR-bee-ah MIL-ee-eye
This plant has low severity poison characteristics.
See below
Description

Crown of Thorns is a deciduous, herbaceous, perennial shrub with bright green leaves and greenish flowers. The flowers are enclosed within long-lasting and bright bracts of red or yellow. The plant is loose in form, spiny and irregularly shaped, with thick, black spines and its historic presence in the Middle East led to the belief by some that the stems of this plant had been used in Christ's crown of thorns, hence the common name. In its country of origin (Madagascar) the plant will grow to 5 or 6 feet tall; however, in the United States, it typically grows to 3 feet, or 2 feet when grown as a houseplant.

Crown of Thorns grows best in dry to medium moisture, well-drained soils in full sun. Because it does not like wet, cold soils or temperatures below 35 degrees F. It is an easy to grow indoor plant where it prefers a sunny location in soil-based potting mix. If grown outside in hot summer climates, provide the plant with midday shade and moderate moisture for better flower bloom. You can propagate the plant from tip cuttings; however, because the resulting white latex sap causes a mild poisonous reaction when in contact with skin or eyes, wear gloves when working with this plant.

Sticky, showy, paired-bract flowers on gray stems with long spines identify this plant. Cyclical leaf drop is normal, but messy and preceeds the plant's resting season (usually winter).  The flowers will bloom throughout the year. The long spines are dangerous to inattentive gardeners, children and pets. The plant is often used as a specimen plant for interiors with high light or as annual outdoor plant. 

Crown of Thorns prefers bright light, dry soil and low relative humidity. You can propagate the plant from cuttings, but let sap dry before placing the cutting in a growing medium.

Diseases, Insects, and Other Plant Problems:

No known serious pests or diseases. As with most indoor plants, potential disease pests include leaf spots, stem and root rots and botrytis blight. Potential insect pests include scale, mealybug, thrips. and mites.

 

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

More information on Euphorbia.

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See this plant in the following landscape:
Cultivars / Varieties:
  • var. splendens
  • 'White Lightning'
    Variegated white and green leaves with a pink tinge
var. splendens, 'White Lightning'
Tags:
#evergreen#poisonous#full sun tolerant#houseplant#cpp#well-drained soil#flowering shrub#spines#fantz#container plants
 
Cultivars / Varieties:
  • var. splendens
  • 'White Lightning'
    Variegated white and green leaves with a pink tinge
var. splendens, 'White Lightning'
Tags:
#evergreen#poisonous#full sun tolerant#houseplant#cpp#well-drained soil#flowering shrub#spines#fantz#container plants
  • Attributes:
    Genus:
    Euphorbia
    Species:
    milii
    Family:
    Euphorbiaceae
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Stem Cutting
    Country Or Region Of Origin:
    Madagascar
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Resistant to rabbits and deer. Tolerates drought and air pollution.
    Edibility:
    Toxic
    Dimensions:
    Height: 3 ft. 0 in. - 6 ft. 0 in.
    Width: 1 ft. 6 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Poisonous
    Shrub
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Dense
    Multi-stemmed
    Maintenance:
    Medium
    Texture:
    Coarse
    Appendage:
    Spines
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Sand
    Shallow Rocky
    Soil Drainage:
    Good Drainage
    Occasionally Dry
    Available Space To Plant:
    3 feet-6 feet
    USDA Plant Hardiness Zone:
    9b, 9a, 10b, 10a, 11b, 11a
  • Flowers:
    Flower Color:
    Gold/Yellow
    Green
    Red/Burgundy
    Flower Inflorescence:
    Cyme
    Insignificant
    Flower Value To Gardener:
    Long-lasting
    Showy
    Flower Bloom Time:
    Fall
    Spring
    Summer
    Winter
    Flower Shape:
    Cup
    Flower Petals:
    Bracts
    Flower Size:
    1-3 inches
    Flower Description:
    Flower bloom time depends on the plant location. When grown in tropical or sub-tropical conditions, blooms occur throughout the year, but especially in Spring and Summer. In warm southern climates, blooms usually occur in winter and spring. When grown as a houseplant, it will bloom from late winter well into fall. Green flowers are subtended by red or yellow showy paired bracts in cymes on long peduncles up to 2 inches. Several miniscule unisexual cyathia, enclosed in a 5-lobed involucre, bear glands and are subtended by a showy pair of bracts. The bracts are ovate, red, salmon or yellow, and about 1/3 of an inch.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Green
    Variegated
    White
    Leaf Feel:
    Smooth
    Leaf Value To Gardener:
    Long-lasting
    Leaf Type:
    Simple
    Leaf Arrangement:
    Whorled
    Leaf Shape:
    Oblanceolate
    Obovate
    Spatulate
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    1-3 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    Evergreen with few, smooth-margined leaves with wedge-shaped bases, produced on new stem growth. Leaves are non-succulent and about 2 inches long. Variegated cultivars exist on the market.
  • Stem:
    Stem Color:
    Gray/Silver
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Angular
    Stem Form:
    Zig Zags
    Stem Description:
    Sharp black spines that can grow to a 1/2 inch long cover the plant's branches and stems. Stems also contain a milky latex of low toxicity. They are grey in color, irregularly branched, and 5-6 sided.
  • Landscape:
    Landscape Location:
    Container
    Houseplants
    Landscape Theme:
    Drought Tolerant Garden
    Design Feature:
    Accent
    Barrier
    Border
    Resistance To Challenges:
    Deer
    Drought
    Dry Soil
    Pollution
    Rabbits
    Problems:
    Contact Dermatitis
    Poisonous to Humans
    Problem for Cats
    Problem for Children
    Problem for Dogs
    Problem for Horses
    Spines/Thorns
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    Causes low toxicity if eaten. Causes minor skin irritation lasting for a few minutes. Ingestion can result in nausea, vomiting, and diarrhea. After some delay, contact with the skin can result in redness, swelling, and blisters.
    Poison Toxic Principle:
    Diterpene esters in milky latex
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Bark
    Flowers
    Fruits
    Leaves
    Roots
    Sap/Juice
    Seeds
    Stems