An ornamental planting of crown of thorns along a wall near Antananarivo, Madagascar

Euphorbia is a large genus of smooth and spiny shrubs and cactus-like succulents from 4” to 20 feet in the spurge family (Euphorbiaceae). Of the more than 1,600 species (including poinsettia, castor bean and cassava), crown of thorns, E.milii is a smallish tropical species from Madagascar that has long been grown as a houseplant or ornamental in warm climates. Many cultivars and hybrids have been developed that vary in flower size and color. The species name milii honors Baron Milius, once governor of the island of Bourbon, who introduced the species into cultivation in France in 1821. The common name refers to a legend that this plant was used as the thorny crown worn by Jesus at his crucifixion. There is evidence that this plant had been brought to the Middle East before the time of Christ, and the stems are flexible enough to weave into a circle, but it is more likely that another plant was used as his crown.

Euphorbia milii in the wild (L) and habitat (R), near Fort Dauphin, Madagascar

The species E. milli grows as a shrubby plant on a woody stem up to 3 feet tall. The variety splendens grows larger, 5-6’, and the hybrids are of various sizes. The greyish brown, branched stems, adapted for water storage, are 5-7 sided. The stem and branches are covered with prominent, 1″ sharp grey spines, although there are some clones that are nearly thornless. The new growth is sparsely covered with narrow succulent leaves. The smooth-edged leaves are 1½”long (some hybrids are much larger, up to 6″ long), obovate (wider near the tip) and are spirally arranged on the stem. The bright green to grayish green leaves naturally drop off as the stems mature, producing a scraggly appearance on older plants. The plant may completely defoliate when stressed (drought or high temperatures), but will later leaf out on new growth.

Typical Euphorbia-type inflorescences are produced throughout the year under ideal conditions. A specialized structure called a cyathium (fused bracts that form a cup) has a single female flower with 3 styles surrounded by five groups of male flowers, each with a single anther, and five nectar glands. Two of those 5 nectar glands have petal-like appendages that most people would consider the “flower”.

The buds (L), open infloresences (LC), inforescence closeup (RC) and closeup of cyathium (R)

On the species these are bright red, or yellow in E. milii var. tananarivae, which is often sold as E. millii var. lutea, but hybrids offer a variety of flower colors from white, cream and yellow, through many shades of pink and red. And some hybrids come in double forms. The flowers are generally produced in clusters (cymes) along the stem (axillary), but some selections bloom in terminal clusters. Sometimes poor flowering is due to too much light at night – these plants need darkness to initiate flowering.

Hybrid cultivars come in a variety of flower colors

Crown of thorns is available in a variety of sizes and colors

Crown of thorns is a quite tough plant in cultivation, taking extreme conditions and still looking good. Several species and cultivars in the E. milii complex were introduced into cultivation in the 1970s that were used in breeding to produce a wide range of plant forms and flower colors. Hybrids of E. milii and E. lophogona (which has long, leathery leaves) produced free-flowering plants with large, thick, deep green leaves. The California hybrids, developed for their stout stems and larger colorful flower bracts, are often referred to as “giant crown-of-thorns” series (e.g. ‘Rosalie’, ‘Vulcanus’, and ‘Saturnus’). German growers made selections of natural crosses in the wild similar to the California hybrids, but with thicker leaves and thinner stems, including varieties such as ‘Somona’ and ‘Gabriella’. The flowers, ranging in color from cream to various shades of pink and red, are often formed within other flowers. Many of these hybrids are patented, and many are marketed in very small pots, as they are tolerant of both drought and over-watering and bloom well in tiny containers. Short and Sweet™ is a compact dwarf cultivar with soft spines that is covered with small bright red bracts. ‘Mini-Bell’ is another dwarf cultivar with a compact growth habit and lots of small red flowers.

Euphorbia milii Thai ‘Yellow Crown of Thorns’

In the early 1990’s new, large flowered hybrids were produced in Thailand. These Thai Poysean hybrids were likely the result of a mutation, rather than selective breeding (Poysean is the name Chinese immigrants used for E. milii). The economic boom conditions of the time and demand for more exotic types of E. milii fueled the development of hundreds of cultivars, with a huge range of flower colors and plant sizes. Instead of just bright red or yellow, there were also many pastel shades, often with blends of different colors. And with cymes with more flowers, some looked more like hydrangeas than the typical crown of thorns. The form of these plants tends to be more upright and compact than the typical straggly-stemmed species, and the leaves are much larger and a brighter green. When the Southeast Asian economy crashed in the late 90’s, most of these cultivars were lost. Now there are only a few major growers near Bangkok that export these plants. The Thai hybrids are popular as collector plants but have not been successfully introduced in Europe or the US as mainstream flowering houseplants. There are many different cultivars available from specialty nurseries. A few include ‘Jingle Bells’ with soft pink bracts tinged with red and green; ‘New Year’ has buttery yellow bracts that change to cherry red as they age; ‘Pink Christmas’ sports cream bracts that develop pale pink and reddish streaks; and ‘Spring Song’ with creamy yellow bracts.

Bright red flowers adorn a crown of thorns

These plants can be moved outdoors for the summer. To prevent sunburn, acclimate them gradually to the higher light levels outdoors. The plants will benefit from rain water, but be sure to remove any dead leaves or matted flowers during periods of prolonged wetness, so that fungal diseases will not develop. Any plant part that turns brown should be cut off immediately so prevent the rot from spreading further.

Crown of thorns is grown as an in-ground plant in mild climates

Crown of thorns is quite tolerant of a range of conditions. This species prefers full, direct sun and average temperatures, but will grow in part shade (although flowering may be reduced). Some hybrids are better adapted to part shade. It will survive temperatures down to about 35F, so plants that are moved outdoors for the summer in the Midwest need to be moved indoors well before frost. It does well in low humidity, so succeeds in heated homes in northern climates. The species and varieties do best when the soil is allowed to dry between deep waterings. Many of the hybrids, however, do better with growing conditions more suitable for tropical foliage plants than typical succulents, and require more frequent watering. Fertilize lightly in spring and summer with a balanced fertilizer. Over fertilization will produce soft and vigorous vegetative growth and few flowers. E. milli is sensitive to boron, so be cautious about using fertilizers with high levels of micronutrients.

Many cultivars of crown of thorns can be kept in small pots

Most types of crown of thorns can be kept in small containers to keep the plants more compact, and will bloom even with restricted root room, but some of the hybrids need larger containers. Repot only when the plant outgrows its container, and replant using a rich, well drained planting medium, such as a commercial cactus mix amended with additional perlite, pumice, sharp sand or gravel and a little extra composted manure or other organic nutrient source. The plant can be set lower in the ground than its original level, particularly if the plant becomes too tall for the container (or to hide the graft union on some of the grafted hybrids). Replant in spring or summer when the plant is growing vigorously.

Crown of thorns is aptly named for the large spines on the branches and stems

Plants can be pruned to keep their shape and size. The milky sap will stick to and gum up cutting implements, so it is best to use a knife that is more easily cleaned, rather than shears. As with other Euphorbias, the copious, sticky, milky sap can cause dermatitis in susceptible individuals and temporary blindness if enough gets in the eyes, and is poisonous if ingested, so use caution when trimming or propagating this plant. Also beware of the sharp thorns! Cut the stems back to axillary buds to increase branching and a more compact habit, or remove entire branches back to their base to open the plant up. Remove weak or thin branches first to improve the vigor of the plant. Hybrids tend to need less pruning than the species, as they have been bred to be more branched and compact.

Crown of thorns is easy to propagate and has few pests

This plant is easily propagated from prunings or stem cuttings. Remove 3-6″ terminal sections and dip the cut end in cold water or powdered horticultural charcoal to prevent the milky sap from running excessively. Allow the cuttings to dry for 2-3 days before placing in well-drained planting mix (such as sharp sand, perlite and peat) to root. Keep the medium just barely moist – if too dry the cuttings will not root, but if too wet they may rot. They should root in 5-8 weeks when temperatures are warm. Potted crown of thorns often become run-down looking after many years; these plants are best discarded after establishing cuttings to replace the original plant. Plants can also be propagated by V cleft grafting using a 2-3″ stem tip on a 2-3″ stump, with ¾” matching wedges. Plants can also be grown from seed, but plants rarely produce seed without hand pollination with different plants.

Crown of thorns has few serious pests. Mealybugs are the most common insect pest in the Midwest, but spider mites, scales and thrips may occur. Diseases generally are the result of too much water, either in the soil or on the foliage.

– Susan Mahr, University of Wisconsin – Madison


Download Article as PDF

Euphorbia Crown Of Thorns Growing: Learn About Crown Of Thorns Houseplant Care

In Thailand it is said that the number of flowers on a Euphorbia crown of thorns plant foretells the luck of the plant keeper. Over the past 20 years, hybridizers have improved the plant so that it produces more and larger flowers (and if the saying is true, better luck) than ever before. In the right setting, hybrids of Euphorbia (crown of thorns) bloom almost year round.

How to Grow Crown of Thorns Indoors

If you’re looking for a plant that thrives in the conditions inside most homes, try the crown of thorns plant (Euphorbia milii). Growing the plant is easy because it adapts well to normal room temperatures and in dry indoor environments. It also forgives occasional missed waterings and feedings without complaint.

Crown of thorns houseplant care begins with placing the plant in the best possible location. Place the plant in a very sunny window where it will receive three to four

hours of direct sunlight each day.

Crown of Thorns Growing Care

From spring through late fall, water the crown of thorns plant when the soil is dry at a depth of about an inch, which is about the length of your finger to the first knuckle. Water the plant by flooding the pot with water. After all of the excess water has drained through, empty the saucer under the pot so that the roots aren’t left sitting in water. In winter, allow the soil to dry to a depth of 2 or 3 inches before watering.

Feed the plant with a liquid houseplant fertilizer. Water the plant with the fertilizer every two weeks in spring, summer and fall. In winter, dilute the fertilizer to half strength and use it monthly.

Repot the plant every two years in late winter or early spring. Crown of thorns needs a potting soil that drains quickly. A mix designed for cacti and succulents is ideal. Use a pot that is large enough to accommodate the roots comfortably. Remove as much of the old potting soil as possible without damaging the roots. As potting soil ages, it loses its ability to manage water effectively, and this can lead to root rot and other problems.

Wear gloves when working with crown of thorns. The plant is poisonous if eaten and the sap causes skin irritations. Crown of thorns is also poisonous to pets and should be kept out of their reach.

Euphorbia milii

  • 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 Leaf Characteristics: Broadleaf Evergreen Habit/Form: 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: Leaf Characteristics: Broadleaf Evergreen Leaf Color: Green Leaf Value To Gardener: Long-lasting Leaf Type: Simple Leaf Shape: Obovate Spatulate Leaf Margin: Entire Hairs Present: No Leaf Length: 1-3 inches 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.
  • Stem: Stem Color: Gray/Silver Stem Is Aromatic: No Stem Form: Zig Zags Stem Description: Sharp black thorns, 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. Stems are spiny, grey, irregularly branched, 5-6 sided, with 1 inch thorns.
  • Landscape: Landscape Location: Container Houseplants Design Feature: Accent Barrier Border Resistance To Challenges: Deer Drought Dry Soil Pollution Rabbits Problems: Contact Dermatitis Poisonous to Humans 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

Crown of Thorns Plant- Euphorbia Milii- Spurge

Crown of thorns or euphorbia is an annual flowering plant in the family Euphorbiaceae. Gardeners grow some of these varieties as ornamental houseplants. These plants are native to North America, South Africa, and Madagascar countries. Thorn plants are grown as landscape because of its drought and heat tolerant properties. The Plant has poisonous milky white sap with floral structures of flower heads. Flowers do not have petals and sepals like other flowering plants. Roots are thick, fleshy and tuberous. Leaves are arranged alternately and appear in whorls.

Here in this article, we shared the detailed information about euphorbias or crown of thorns which is used as the air-purifying plant and as ornamental plants to decor your home.

These plant leaves turn yellow, root rot and pests & disease problem. It is mainly due to the lack of caring for the euphorbia plants. We come up with a solution to these sort of problems and you can know them detailed in this article.

Euphorbia Varieties

There are more than 2000 varieties cultivated worldwide for its ornamental purposes and fragrant flowers. Many of these plant species are succulent, thorny and grow well in tropical & sub-tropical regions of warm temperatures.

S. No Plant Variety
1 Euphoriba Milii Bevilaniensis
2 Euphoriba Milii Hislopii
3 Euphoriba Milii Imperatae
4 Euphoriba Milii Longifolia
5 Euphoriba Milii Roseana
6 Euphoriba Milii Tenuispina
7 Euphoriba Milii Vulcanii

How to Grow Crown of Thorns Plant?

Euphorbia plants are popular houseplants of your garden. These plants may vary in hardy temperate zones. Here is the step by step procedure to grow crown of thorns starting from seeds.

Crown of Thorn Plant Information

Family : Spurge

Scientific Name : Euphorbia milii

Origin : Madagascar

Soil : Well-drain fertile soil with 6-7.5

USDA Zone : 8-11

Sunlight : Full sun to partial shade

Temperature : 60-90F

Plant Height : 5-6 feet

Flowers : Red, pink, white, yellow

Fertilizers : N-P-K fertilizer, Baking soda

Harvesting Time : 1-2 years

Choose a Seed Variety

Select a silver leaf seed variety that is well suited to grow in a sunny location. Euphorbia myrsinites and euphorbia rigida varieties are good to grow to start from seeds. Variegated Euphorbia looks best in bright places if they grow in warmer climates.

Pot & Soil

Choose a pot of size 6-8 inches tall to start growing from seeds. The pot is made up of clay or ceramic and has holes at the bottom to drain water completely.

Euphorbia plants are tolerant to low-quality soils and usually prefer well-drain soil so that the air can circulate within the roots. Either you can prepare soil or buy from a nursery store containing 2 parts soil and 1 part peat moss, sand, and perlite.

Water & Sunlight

Provide them light moisture by supplying sufficient amount of water to the plants. It helps to prevent the powdery mildew disease when watered under the plant roots.

Euphorbia plants thrive quickly when the room temperature is between 65-75F. These plants can withstand if the temperature is below 50F in winter season and 90F in the summer season. Seeds germinate slowly and may take 2-3 weeks to month time. These plants do not like disturbing the roots so the best place to grow them pots.

Nutrient Deficiency

S. No Element Deficiency symptom
1 Nitrogen Yellowish green leaves, curled, wrinkled
2 Phosphorus Light green color leaves and dried petals
3 Potassium Dark green and erected leaves
4 Magnesium Yellow leaves, interveinal chlorosis

Pests & Diseases

Pests Diseases
Mealybugs Powdery mildew
Spider mites Root rot
Aphids Damping off
Thrips Tobacco mosaic virus
Caterpillars Leaf yellowing
Nematodes Fusarium wilt

Pollination

It is the process in which pollens are transferred from stamen to stigma through wind and insects like honey bees, hummingbird, and beetles. Pollination in euphorbias can be achieved by using a brush with fine hair and transferring the ripe pollen.

Pruning

To keep the crown of thorns plants to the ground level, cut back the branches while leaving the auxiliary buds and sprouts. Remove dead leaves and flowers from the surface of the soil. This will help the soil to aerate and prevent from fungal diseases.

Fertilizers

Thorn plants remain healthy even though you do not fertilize the plant occasionally. Watering too much helps to dissipate chlorine from the soil. So as to improve the soil fertility and flower blooming use a balanced fertilizer N-P-K in the ratio for 10-10-10. If you don’t find an NPK fertilizer then you can use organic compost, manure and Baking soda for better growth of euphorbias. Apply the fertilizers once in a week during the growing season around the base of the plant, where weather begins to cool and days become shorter.

Harvesting

During the 1st growing season euphorbias will not bloom flowers. They start blooming flowers from the 2nd season and some other varieties may take years. To harvest the fragrant flowers, the plant should mature completely and reach to a height of 2-3 feet tall.

Now harvest the euphorbia flowers early in the morning or evening using a sharp knife or scissors or simply pluck flowers using hands. Wear gloves so as to protect yourself from allergies.

Can you Propagate Crown of Thorn Plants from Cuttings?

To propagate euphorbias, you can prefer stem cutting or V-grafting method to grow. Propagating this method from cuttings is easy than growing from seeds which take less time to mature the plant and flower blooming.

Stem Cuttings

During spring season the flower buds emerge, take tip cuttings with 3 pairs of leaves and by cutting (1/4) inch below the leaves. Here is the simple procedure that completely explains the growth of crown of thorn plants from cuttings.

  • Take a stem cutting of size 6 inches from a healthy thorn plant and the selected stem should be young but not too small.
  • Trim off the lower leaves of the stem cutting using a sharp knife or blade.
  • Now place the stem cutting in a jar of water and change water for every 2-3 days.
  • Place the entire setup near window location to receive sunlight for a minimum of 6-8 hours a day.
  • It helps cuttings to get sufficient nutrients and may take 2-3 weeks time to establish roots.
  • Euphorbia plant matures, grows to a height of 2-3 feet tall and is ready to transplant outdoors.

This method is mostly preferred to recover the plant from root rot. It is an excellent way to add new species to your garden space.

V-Grafting

Euphorbia plants can also be propagated through V-grafting method. This grafting method is mostly used for its cultivators by growers. Grafting is mostly used to join parts from 2 or more plants so as to appear as a single plant. In this method, the upper part of the plant grows on the root stem of another plant.

The stock plant is cut 2-3 inches above the soil and a deep V-shaped is made into the stock. Now insert scion into the stock and wrap together using a grafting tape. This grafting method helps to promote the plant growth by producing fragrant flowers with high yielding crop plants.

Division Method

You can easily propagate crown of thorns by the division of parent plants. Take out the plants from the ground level and remove the soil from roots by washing with water. Allow the roots to dry for some time or cut immediately with a sharp knife. Each division must have several eyes and roots to propagate effectively.

Now place the crown of thorn plant division in a well-drain fertile soil. Water the divisions regularly and allow it to receive sunlight (6 hours a day) by placing it near window site. When it grows to a height of 10-12 inches tall you can transplant it to outdoors or encourage growing landscape.

How do you Care for Euphorbia Plants?

  • Do not place the euphorbia plants in extremely cool conditions.
  • Make sure the plant receives sunlight for a minimum of 6-8 hours a day.
  • Avoid using fungicides as it can damage the foliage of Euphorbia plants.
  • Use clay or ceramic pot that has holes at the bottom for proper drainage.
  • Re-pot the thorn plant every year in the spring season when the root grows rapidly.
  • Keep children and pets like dogs & cats away from the plants when you fertilize.
  • Wear protective clothes, gloves, and goggles while pruning the crown of thorns plant.
  • Fertilize the plants with organic matter once in every week during the growing season.
  • Follow the instructions & warning labels on covers when you purchase them before planting.
  • Do not overwater as the plant absorbs too much of water from roots and result in root rot disease.
  • Adding mulches (dead leaves, ripe fruits & vegetables) at the base of the plant to improve soil fertility and maintain moisture levels.

What are the good companion plants for euphorbia plants?

Combine euphorbia plants with bulbine, succulents, leucadendron, lavender, purple heart and salvias to improve the plant growth. These companion plants help to deter pests, improve soil fertility and overcome diseases problem when planted in the outdoor garden.

How deep should you plant in the soil?

The stem cutting should be planted in such a way to a depth that will remain secure. If you insert too much of the stem into the soil then it may absorb more amount of water which results in root rot disease. So it’s better to plant euphorbias 4-6 inches deep under the ground level to support the base with strings. add a layer soil containing 2 parts of garden soil and 1 part peat moss, sand & perlite.

How often you water crown of thorns?

You can start watering crown of thorns plant when it reaches to a height of few inches (hardly8-12 inches). Water the plant regularly in small amounts. During the summer season, water the plant in excess (1-2 inches per week) so as to withstand in extreme hot climatic conditions and very often in winter.

Will euphorbias survive in winter?

Euphorbias plants can tolerate full sun to partial shade conditions. It is a hard flowering crop plant that is grown for its beautiful ornamental fragrant flowers. When you start planting euphorbias bring it to indoors (rooms) as the young plant of size 6-8 inches cannot tolerate cool weather conditions. But mature euphorbia plants can withstand up too 50F in the winter season.

How to repot crown of thorns?

Crown of thorns or christ plant has thorns lining at its stems and branches. In addition to the pruning, you must repot the thorn plants in summer season of every year. As it grows bigger and bigger the plant leaves, stems and roots develop accordingly. So when you have planted the thorns in pots, there may be chances of roots emerging out of the pot. At this stage, you need to repot the plant for a better growth.

Why my crown of thorn leaves turning yellow?

Stems of thorn plant get mushy and the leaves fall off, turn yellow when the soil is too wet. To overcome this problem move your thorn plant to a warm bright location where there is good air circulation. Allow 50% of the soil of crown of thorns plant to dry out before you water the plant again.

For more information: Why are my plants turning yellow?

Is Euphorbia plant poisonous?

Yes, euphorbia plants are poisonous as it contains poisonous sap even when touching the plant. The sap of the plant is typically milky white and much dangerous to your pets when the consumed result in drooling, allergic reactions, vomiting and diarrhea symptoms.

What are the medicinal uses of the crown of thorn plants?

The plant is often used as traditional Chinese medicine and as hedging plants in many parts of Africa. Some parts of the plant above ground contain a chemical compound called ingenol mebutate in medicine to treat asthma, chest congestion, and bronchitis. Few people use the plant leaves to cause vomitings.

Start growing crown of thorns plants in pots or outdoors that adds beauty to your home garden. If you have amazing ideas about growing crown of thorns, please share your experience with us in the comment section.

Recommended Readings

  • Aloe Vera Plant Care – Best ways to Care Aloe Vera at Home
  • Best Plants To Keep In Your Bedroom To Help You Sleep
  • Fern Plant Care- How do you take Care of a Fern at Home and Garden?

The Crown of Thorns plant (Euphorbia Milii) originally grew in Madagascar. This succulent shrub holds multiple stems and dark green leaves.

Thorns cover the branches. However, they feel relatively soft when touched making them not too difficult to work with.

The Crown of Thorns plant started to become popular during the Victorian era. Euphorbia Milii has several common names including:

  • Crown of Thorns
  • Christ plant
  • Christ thorn

A recent great deal of cultivar development and hybridization took great interest on the crown of thorns. It resulted to a tremendous amount of choice in flower color and plant blossom size.

In addition to being an excellent houseplant, you can plant Euphorbia milii outdoors in the warm climates of USDA hardiness zones 9B through 11.

In this article, we will share information on growing crown of thorns. It will also provide tips on propagation and solutions for pests and diseases.

Crown Of Thorns Plant Characteristics

Apart from being an evergreen plant, Euphorbia Milli can also resist drought. It produces woody, succulent stems up to three feet high. The thorns cover the stems randomly and measure up to an inch long.

The bright green leaf bracts grow randomly and slightly sparse. They appear mostly on newer stems and fall away from the older stems. This means you can only find leaves on the youngest and newest portions of the plant.

Blooms appear mostly throughout the spring and late into the summer. However, in ideal conditions, the plant can produce flowers year-round.

To monitor the well-being of your crown of thorns, always check on its leaves. Sporadic shedding from mature stems does not indicate a problem. But if all of the leaves fall off suddenly, it signals stress which poses a threat to your plant.

If a sudden decrease in leaves happens, you must take the necessary steps to determine its cause. More often than not, excessive watering or poor drainage usually result to this. After solving the problem, the leaves may grow healthy again.

Daily Caring For Euphorbia Milii

Although crown of thorns belongs to the species of Euphorbia succulent plants, it can only store a limited amount of water using its stems. The plant also takes in water through the leaves, so misting the plant on a daily basis may help.

In fact, spraying with a weak saline solution works great because this plant does well at the seaside in full sun.

The plant needs minimal nourishment but does respond to slow-release fertilizer, and it does very well in poor but well-drained soil.

However, a special cactus soil mix would be best.

The root ball should not remain moist for an extended period to avoid root rot.

This plant has a high drought tolerance. However, the best way to water succulents like this plant is on a weekly basis and remember to allow the soil to dry completely.

Keep The Atmosphere Sunny And The Soil Light

This succulent plant hungers for sunlight. If you want the crown of thorns as a house plant, position it in a bright, sunny window on the west or south side of your home. Unlike many houseplants, bright light and likes direct sunlight.

When planting outside, a sunny rock garden makes an excellent setting. If mixed in with cactus and other xeriscape type plants, the crown of thorns looks very attractive.

As with all succulents and cacti, provide the soil with excellent drainage. A soil mixture containing about one-third perlite or pumice makes a good well-drained soil option.

The plant grows well if placed under direct bright light in areas with cooler summers. In the regions governed by scorching, summer weather, set the plant in areas with good afternoon shade to avoid withering.

Do not overdo with the shade as too much of it results in reduced flower production.

In outdoor containers, you may use a prepared cactus soil mix. Give the pot plenty of drainage holes and place it in a place where it can get ample sunlight.

Start your planting process with a layer of gravel on the bottom to ensure excellent drainage.

How To Fertilize Crowns Of Thorns

Although the crown of thorns remains healthy even without fertilizers, an occasional, diluted dose of basic fertilizer helps with bloom production. However, choose a type of fertilizer without boron as the plant reacts sensitively to this micronutrient.

This interesting succulent does not grow quickly and does not need a large amount of fertilizer. In the landscape, you should use a diluted solution of a balanced fertilizer (10-10-10) once a month in the springtime and throughout the summer. If using a granulated fertilizer, give four tablespoons per 10 square feet.

In outdoor containers, use a water-soluble liquid fertilizer (3–1–2 ratio) at a rate of half a teaspoon per gallon of water. Apply this dose every month. The same dosage also serves as an excellent solution for houseplants.

Maintenance And Pruning

Prune lightly (our favorite pruners here) to maintain the size and shape of your plants. Although evergreen, the crown of thorns naturally grows more vigorously throughout the spring and summer.

In the autumn, remove old branches with most of its leaves withered. This will stimulate more new growth when springtime arrives.

Remove dead, fallen leaves, and flowers from the surface of the soil. This will help with soil aeration and prevents fungal disease. Moreover, cut background leaves, stems, and other unattractive growth.

Avoid contact with the milky sap of the plant when you trim. This toxic, milky, white sap causes skin irritation and eye problems.

In fact, getting the fluid in your eyes can result in temporary blindness. For this reason, always wear gloves, goggles, and other protective clothing when pruning the plant.

Clean your pruners thoroughly after each use. Wash the tool with water and wipe it clean using a cloth disinfected with rubbing alcohol.

Crown of thorns is one of the many good indoor plant types for greening your home. Floor plants, desktop plants, flowering plants and more.

Learn more – Is the Crown of Thorns Plant Poisonous?

What To Do With Crown Of Thorns During Winter Month

Letting houseplants stay outside in the summertime seems like a good idea. On the other hand, it takes little cold and damp to kill a crown of thorns or to get root rot started.

For this reason, move both container plants and potted plants indoors before the onset of rain or the winter season.

Transition the crown of thorns gradually when you move them back outdoors in the springtime.

Acclimate your plants by placing them outdoors in partial shade for one or two weeks before moving them into bright sunlight.

Check for all danger of frost and make sure those already melted before acclimation.

Diseases And Pests

Generally speaking, infestations and diseases plague crown of thorns rarely. However, plants kept indoors may occasionally encounter problems with spider mites on plants, different types of scale insects, and playing host to mealybugs.

As a solution to pests, wipe the foliage with a cotton ball or cotton swab dipped a few seconds in soapy water. You can also wash your plant under running water but try not to soak the soil. Otherwise, it may lead to a root rot.

Crown of thorns can acquire root rot if overwatered or planted in dense soil. If root rot sets in, saving the plant becomes highly impossible. You may need to take cuttings and start over.

More on –> Succulent Root Rot

How to Propagate

Making new plants and growing crown of thorns makes an easy planting hobby. Read on to learn more.

  • Simply take tip cuttings from your younger branches during the growing season. Use a clean, sharp blade (e.g. a razor blade) to take the cutting at the point where the branch meets the trunk.
  • Quickly dip the end of your cutting into warm water to prevent the sap from running out.
  • Lay your cuttings on a paper towel or newspaper for a few days to dry and callus the ends.
  • Prepare a pot of damp sand.
  • Dip the callused ends of the cuttings into a rooting hormone product like this one.
  • Poke the callused ends of your cuttings into the wet sand.
  • Place the pot in a warm (75°F) location with bright indirect light and wait. Refrain from watering for a couple of weeks.
  • Within a few weeks, your cutting will develop roots. You can tell by tugging gently on the cutting. If it offers resistance, you know that roots formed already.
  • After about a month, new signs of growth will appear. At this point, begin watering lightly.

Use this method to help your plant recover from root rot. This also works great with propagating your crown of thorns plants.

Propagation of cuttings makes an excellent way to add new and exciting specimens to your collection.

Crown Of Thorns Varieties

A wide range of hybrids and cultivars makes up the list of available Euphorbia Milli species. Look for interesting specimens such as:

  • American Beauty – produces incredibly gorgeous scarlet red blossoms.
  • Short and Sweet – this Euphorbia belongs to the dwarf category. It also produces showy, very attractive bright red bracts we call “red flowers.”

Some of the “New” Crown Of Thorns on the market!

  • Hot Pink Crown of Thorns – Loves a sunny location
  • Golden Crown of Thorns Known as Euphorbia splendens ‘Dinni’

While red serves as the traditional blossom color for these popular house plants, an entire group of California hybrids also features strong and sturdy stems. They appear enormous and hold larger flowers in colorful hues ranging from pink to peach to yellow. Among these are:

  • Vulcanus
  • Saturnus
  • Rosalie

Above lists a few of the intriguing cultivars and hybrids available today. Below are several

Apart from being easy to grow, they look great and even stand out from a bunch of potted plants.

Gathering a complete collection of crown of thorns plants for your home and garden functions is a fun, fascinating and absorbing hobby.

Crown Of Thorns Euphorbia: Tips On Growing Crown Of Thorns Outdoors

With a common name like “crown of thorns,” this succulent needs some good publicity. You don’t have to look very far to find great attributes. Heat tolerant and drought resistant, the crown of thorns plant is a real gem. You can plant crown of thorns in the garden in warm climates. Read on for tips about growing crown of thorns outdoors.

Growing Crown of Thorns Plant Outdoors

Lots of people grow a crown of thorns plant (Euphorbia milii) as a unique houseplant, and unique it is. Also called crown of thorns euphorbia, it’s one of the few succulents with real leaves – thick, fleshy, and tear-shaped. The leaves appear on stems that are armed with sharp, inch-long spines. The plant gets its common name from the legend that the thorny crown worn by Jesus at his crucifixion was made from

sections of this plant.

The crown of thorns euphorbia species hails from Madagascar. The plants first came to this country as novelties. More recently, growers have developed new cultivars and species that make growing crown of thorns outdoors more attractive.

If you are lucky enough to live in one of the warmer areas of the country, you’ll enjoy growing crown of thorns outdoors as a small shrub outdoors. Plant crown of thorns in the garden in U.S. Department of Agriculture plant hardiness zone 10 and above. Sited correctly, the plant offers a mass of delicate blossoms all year round.

Crown of thorns is great as an outdoor shrub in warm climates, as it is extremely tolerant of high temperatures. It even thrives in temperatures above 90º F. (32 C.). You can add this flowering succulent to your garden without worrying much about maintenance. Caring for outdoor crown of thorns is a cinch.

Caring for Outdoor Crown of Thorns

Plant crown of thorns euphorbia shrubs in full sun for best blossoms. The plants also tolerate salt spray. As with any shrub, a crown of thorns plant needs irrigation after transplant until its root system gets established. After that, you can cut back on water thanks to its great drought tolerance.

If you love the crown of thorns in the garden and want more, it’s easy to propagate from tip cuttings. Just be sure to protect it from frost and freeze. You can propagate crown of thorns from tip cuttings. You’ll want to wear thick gloves before you try this, though. Your skin can get irritated from both the spines and the milky sap.

Crown of Thorns

In many areas of the country, crown of thorns is grown as a unique houseplant. For Florida gardeners it makes a great container plant, and in South Florida, it can also be planted outdoors as a small shrub.

Native to Madagascar and classified as a succulent, crown of thorns (Euphorbia milii) has thick fleshy leaves and stems adapted for water storage. One of the reasons crown of thorns makes such a great choice for Florida gardens is that it’s heat tolerant and tolerates salt spray. Because it doesn’t mind drying out, it makes a good flowering container plant.

A tropical relative of poinsettias, crown of thorns is perhaps best known for its interesting stems, which are grayish brown and covered with inch-long spines. Gardeners also appreciate that it blooms year-round with delicate flowers in pink, red, yellow, or white.

Plant it in full sun for best results, watering as needed. Once established, it has good drought tolerance. Just be sure to protect it from frost and freeze. You can propagate crown of thorns from tip cuttings, but take care when handling the plant. Both the spines and the milky sap can cause skin irritation.

UF/IFAS Publications

Also on Gardening Solutions

  • Coastal Landscapes

25 Years of Nonstop Blooms — Thank You, Crown Of Thorns

Photo: Steve Bender

Lots of plants are called “everblooming,” but when you get them home you find out the story is a bit different. Some skip a week, some skip a month, and you get ticked off. Today, I present a truly everblooming plant — one that has never missed a single day in the 25 years I’ve had it. It’s called crown of thorns .

Crown of thorns (Euphorbia milii) is a small, woody shrub that gets its name for the sharp, half-inch long thorns that cover its main stems. Some people claim that its branches were cut to make the crown the Romans put on Jesus. I rather doubt this for several reasons. First, the plant is native to Madagascar — a fer piece from Calvary. Second, its thorns are too short to do the job the Romans wanted. Finally, if you’re looking to make a crown from a thorny shrub or tree in the Holy Land, the place abounds with better, more painful choices.

Anyway, don’t let the thorns put you off. My plant has never stuck me. Why? Because like the genius I am, I pick it up by the pot, not the stems.

Image zoom emPhoto: amazon.com/em

My crown of thorns plant started out about the size of the little plant above. I bought it a quarter-century ago to combine with other low-water plants in a small, stone container I called “A Desert in a Dish.” That six-inch wonder bloomed from day one. I eventually transferred it to its own pot. It now stands about 24 inches tall and is blooming as I type.

The true flowers are inconspicuous, but like poinsettia (another species of Euphorbia) they’re overshadowed by colorful bracts that resemble petals. Red is the usual color, but I’ve also seen pink, yellow, orange, and white.

Thai Giants are hybrids presumably bred in Thailand that grow about as tall as regular crown of thorns, but have flowers, thorns, and leaves twice as big. They also boast a wide range of colors and color combinations, like the plant shown below.

Image zoom emA Thai Giant. Photo: ebay.ca/em

The Giants can be spectacular, but I prefer the species because it’s less coarse. I’ve also noticed the Giants going through rest cycles, something that the species never does when grown in a pot.

Where to Grow It

Image zoom emPhoto: pictureplants.com/em

If you live where it never freezes, you can grow crown of thorns outdoors in the ground. But you probably don’t, so you’ll have to grow it in a pot you can bring inside to a bright window when it gets cold. Mine comes indoors when the temp drops below 40 degrees. Below 32 degrees, your plant will be injured or die.

How to Grow It Crown of thorns is extremely easy to grow. I’ve never seen a single bug or fungus on mine. All it wants is sun and well-drained soil. If the soil goes completely dry, the leaves may shrivel and drop and blooming ceases. However, soon after you water, it’ll shoot out more leaves and flowers. Old flowers drop as new ones pop. Drought tolerance makes it good for arid climates, but it also does just fine in high-rainfall areas like central Alabama where Grumpy lives. Just make sure the pot drains well. Feed potted plants with a liquid all-purpose fertilizer about every two weeks from spring through summer.

Sources Crown of thorns is widely available at local garden centers and greenhouses starting in the spring. If you can’t find it there, try these mail-order nurseries.

Logee’s Greenhouses

Top Tropicals

Leave a Reply

Your email address will not be published. Required fields are marked *