Crown of thorns needs bright sunlight and careful watering to avoid root rot. If you want to know how to grow crown of thorns successfully, you have come to the right place. This tough succulent is forgiving for beginners but does best with a few specific care tips. Let’s get straight into it.
Understanding The Crown Of Thorns Plant
This plant, also known as Euphorbia milii, is native to Madagascar. It gets its name from the sharp thorns on its stems. The “flowers” are actually colorful bracts that come in red, pink, yellow, or white. They bloom almost year-round with proper care.
The plant stores water in its thick stems. This makes it drought-tolerant but also prone to rot if overwatered. It can grow up to 3-6 feet tall outdoors, but stays smaller in pots.
Why Grow Crown Of Thorns
It is low-maintenance and blooms constantly. It handles neglect better than most houseplants. The plant is also deer-resistant and thrives in hot, dry conditions. Perfect for forgetful waterers.
How To Grow Crown Of Thorns: Step By Step Guide
Here is the complete process for growing this plant from start to finish. Follow these steps and you will have a happy, blooming crown of thorns.
Choosing The Right Pot And Soil
Use a pot with drainage holes. Terracotta pots work best because they help soil dry faster. The pot should be only 1-2 inches wider than the root ball.
Soil must drain quickly. Regular potting soil holds too much water. Mix your own with:
- 2 parts cactus or succulent mix
- 1 part perlite or coarse sand
- 1 part small pumice or gravel
This mix prevents water from sitting around the roots. You can also buy a pre-made cactus soil and add extra perlite.
Light Requirements For Crown Of Thorns
This plant needs bright, direct sunlight for at least 4-6 hours daily. A south-facing window is ideal. Without enough light, the stems become leggy and bloom stops.
If you live in a hot climate, some afternoon shade can prevent leaf burn. But generally, more sun equals more flowers. You can move the plant outside in summer for better growth.
Watering Schedule That Works
Water only when the top 2 inches of soil feel dry. Stick your finger in the soil to check. In summer, this might be every 7-10 days. In winter, every 2-3 weeks.
When you water, do it thoroughly until water drains out the bottom. Empty the saucer after 15 minutes. Never let the pot sit in water.
Signs of overwatering: yellow leaves, mushy stems, or a bad smell from the soil. If you see these, let the plant dry out completely before watering again.
Temperature And Humidity Needs
Crown of thorns likes warm temperatures between 65-85°F (18-29°C). It can handle short periods down to 50°F, but frost will kill it. Bring it indoors if temps drop below 50°F.
Humidity is not important. Normal room humidity works fine. Avoid misting the leaves as this can cause rot.
Fertilizing For More Blooms
Feed the plant every 2-4 weeks during spring and summer. Use a balanced liquid fertilizer diluted to half strength. A fertilizer with higher phosphorus (like 10-30-10) encourages more flowers.
Stop fertilizing in fall and winter when growth slows. Too much fertilizer can burn the roots or cause leggy growth.
Propagation: How To Grow Crown Of Thorns From Cuttings
Propagation is easy and gives you free plants. The best time is spring or early summer. Here is the step-by-step method.
Taking The Cutting
- Wear thick gloves. The sap is toxic and can irritate skin.
- Use clean, sharp scissors or pruners.
- Cut a stem tip that is 4-6 inches long. Make the cut just below a leaf node.
- Dip the cut end in water to stop the sap flow, then let it dry for 2-3 days. This calluses the cut and prevents rot.
Rooting The Cutting
- Fill a small pot with moistened cactus mix.
- Insert the callused end about 1-2 inches into the soil.
- Place the pot in bright, indirect light. No direct sun yet.
- Water sparingly—only when the soil feels dry. Overwatering will rot the cutting.
- Roots should appear in 3-4 weeks. You can gently tug the stem to check for resistance.
Once roots are established, move the pot to a sunny spot and care for it like a mature plant.
Common Problems And Solutions
Even with good care, issues can happen. Here are the most common problems and how to fix them.
Yellow Leaves Falling Off
This is normal for older leaves, but if many leaves drop, check watering. Overwatering is the usual cause. Let the soil dry out completely. Also check for drafts or sudden temperature changes.
No Flowers Or Few Blooms
Lack of sunlight is the top reason. Move the plant to a brighter spot. Also, too much nitrogen fertilizer can stop blooming. Switch to a bloom-boosting fertilizer with higher phosphorus.
Leggy Or Stretched Stems
This means the plant is reaching for light. Move it closer to a window. You can prune back leggy stems to encourage bushier growth. Cut just above a leaf node.
Pests: Mealybugs And Spider Mites
These pests sometimes attack crown of thorns. Wipe leaves with a cotton swab dipped in rubbing alcohol. For severe infestations, use insecticidal soap. Keep the plant clean and dust-free.
Root Rot
This is the most serious problem. If stems feel soft or mushy at the base, the roots are rotting. Remove the plant from the pot, cut away all rotten roots, and repot in fresh, dry soil. Water very sparingly for a few weeks.
Pruning And Maintenance Tips
Pruning keeps the plant compact and encourages branching. Do it in early spring before new growth starts.
- Always wear gloves to protect from thorns and sap.
- Cut back leggy stems to a leaf node or side branch.
- Remove dead or damaged stems completely.
- You can shape the plant by cutting back taller stems.
After pruning, the plant will produce new branches and more flowers. The cuttings can be used for propagation.
Potting And Repotting Guide
Repot every 2-3 years or when roots fill the pot. Spring is the best time. Choose a pot only one size larger. Too big a pot holds excess moisture and causes rot.
Steps for repotting:
- Water the plant a day before to reduce stress.
- Gently remove the plant from its old pot.
- Shake off old soil and trim any dead or circling roots.
- Place in the new pot with fresh cactus mix.
- Water lightly and keep in bright, indirect light for a week.
Growing Crown Of Thorns Outdoors
In warm climates (USDA zones 9-11), you can grow crown of thorns in the ground. Choose a spot with full sun and well-draining soil. Raised beds work well if your soil is heavy clay.
Space plants 2-3 feet apart. Water deeply but infrequently once established. Mulch around the base to keep roots cool, but keep mulch away from the stem.
In colder zones, grow in containers and move indoors before frost. You can also dig up outdoor plants and overwinter them in pots.
How To Grow Crown Of Thorns In Water
Some people try water propagation. It is possible but not recommended for long-term growth. The roots that form in water are different from soil roots. If you move the plant to soil later, it may struggle.
For short-term display, you can root a cutting in water. Change the water every few days. Once roots appear, plant in soil as soon as possible.
Seasonal Care Guide
Spring And Summer
This is the active growing season. Water more often as the soil dries faster. Fertilize every 2-4 weeks. Move plants outside if temperatures are above 60°F at night. Prune and repot in early spring.
Fall And Winter
Growth slows down. Reduce watering to every 2-3 weeks. Stop fertilizing. Keep the plant in a warm, bright spot indoors. Protect from cold drafts. The plant may drop some leaves, which is normal.
Safety Precautions
The sap of crown of thorns is toxic and can cause skin irritation, redness, and swelling. If ingested, it causes mouth and stomach irritation. Keep the plant away from pets and children.
Always wear gloves when handling the plant. Wash hands immediately after contact. If sap gets in your eyes, rinse with water and seek medical help.
Frequently Asked Questions
How often should I water my crown of thorns?
Water when the top 2 inches of soil are dry. In summer, this is about once a week. In winter, every 2-3 weeks. Always check soil moisture first.
Why is my crown of thorns not blooming?
Most likely not enough sunlight. Move it to a brighter spot with direct sun for 4-6 hours daily. Also check if you are using too much nitrogen fertilizer.
Can crown of thorns grow indoors?
Yes, it grows well indoors if given bright, direct sunlight. A south-facing window is best. It can also grow under grow lights.
Is crown of thorns toxic to cats and dogs?
Yes, the sap is toxic if ingested. It can cause drooling, vomiting, and irritation. Keep the plant out of reach of pets.
How do I make my crown of thorns bushier?
Prune the stems back in early spring. Cut just above a leaf node. This encourages branching and a fuller plant.
Final Thoughts On Growing Crown Of Thorns
This plant is one of the easiest succulents to grow. It rewards you with constant blooms and needs very little attention. The key is bright light and careful watering. Avoid wet soil and cold temps.
Now you have all the information you need on how to grow crown of thorns. Start with a healthy plant, give it the right conditions, and you will enjoy its beauty for years. Remember to wear gloves when handling it. Happy growing.