Crown-of-thorns Euphorbia milii
Other Common Name(s):
- 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. Be sure to wear gloves to prevent skin and eye irritation.
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.
- Profile Video:
- See this plant in the following landscape:
- Cultivars / Varieties:
-
- 'Century' hybrid
yellow flowers, the petal edges are shaded pale pink - 'Cherokee'
tall variety, up to 6 feet, bright red flowers - 'Crimson Splash' hybrid
large flowers with white petals and splashes of crimson red - 'Full of Money' hybrid
flowers in shades of pink, red, and yellow - 'Peppermint Candy'
variegated leaves of green and white with bright red flowers - 'Pink Jewel' hybrid
flowers are in shades of cream and light pink when they open then become a vivid pink - 'Red Hot' hybrid
vibrant red flowers - var. splendens
rambling habit, up to 5 feet tall, 3 feet wide, short oblong leaves, yellow flowers with red bracts - 'White Lightning'
Variegated white and green leaves with a pink tinge
- 'Century' hybrid
- 'Century' hybrid, 'Cherokee', 'Crimson Splash' hybrid, 'Full of Money' hybrid, 'Peppermint Candy', 'Pink Jewel' hybrid, 'Red Hot' hybrid, var. splendens, 'White Lightning'
- Tags:
- Cultivars / Varieties:
-
- 'Century' hybrid
yellow flowers, the petal edges are shaded pale pink - 'Cherokee'
tall variety, up to 6 feet, bright red flowers - 'Crimson Splash' hybrid
large flowers with white petals and splashes of crimson red - 'Full of Money' hybrid
flowers in shades of pink, red, and yellow - 'Peppermint Candy'
variegated leaves of green and white with bright red flowers - 'Pink Jewel' hybrid
flowers are in shades of cream and light pink when they open then become a vivid pink - 'Red Hot' hybrid
vibrant red flowers - var. splendens
rambling habit, up to 5 feet tall, 3 feet wide, short oblong leaves, yellow flowers with red bracts - 'White Lightning'
Variegated white and green leaves with a pink tinge
- 'Century' hybrid
- 'Century' hybrid, 'Cherokee', 'Crimson Splash' hybrid, 'Full of Money' hybrid, 'Peppermint Candy', 'Pink Jewel' hybrid, 'Red Hot' hybrid, var. splendens, 'White Lightning'
- Tags:
-
-
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:
- Houseplant
- 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:
- 9a, 9b, 10a, 10b, 11a, 11b
-
-
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:
- The milky white latex sap found in all plant parts can cause mild to severe contact dermatitis. If contact with the eyes occurs the sap can cause temporary to permanent damage to the cornea. If eaten, blistering can occur on lips and oral mucosa. Avoid ingesting plant parts and keep plants away from pets and children.
- Poison Toxic Principle:
- Diterpene esters in milky latex
- Causes Contact Dermatitis:
- Yes
- Poison Part:
- Bark
- Flowers
- Fruits
- Leaves
- Roots
- Sap/Juice
- Seeds
- Stems
