Euphorbia Milii Plant- How To Grow and Care For Crown of Thorns Plant

Euphorbia Milii Plant- How To Grow and Care For Crown of Thorns Plant

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


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.


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.


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.


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.   

Euphorbia Milii Plant- How To Grow and Care For Crown of Thorns Plant

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.


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.

Euphorbia Milii Plant- How To Grow and Care For Crown of Thorns Plant

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.

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