A low-fuss, blooming succulent with attitude—spikes, flowers, and year-round charm.
Euphorbia milii, or Crown of Thorns, is a spiny, flowering succulent native to Madagascar. It’s beloved for its brightly colored bracts, thorny stems, and incredible ability to bloom indoors almost year-round if it gets enough light. This plant isn’t shy—it puts on a show with minimal care and is tolerant of neglect.
Its biblical nickname comes from its thorny stems, said to resemble the crown placed on Christ’s head. But don’t let the drama fool you—it’s one of the easiest indoor succulents to care for.
Quick Care Guide
| Feature | Detail |
|---|---|
| Common Names | Crown of Thorns, Christ Plant |
| Botanical Name | Euphorbia milii |
| Family | Euphorbiaceae |
| Plant Type | Succulent shrub |
| Mature Size | 1–3 ft tall indoors |
| Sun Exposure | Full sun to partial shade |
| Soil Type | Sandy, well-draining |
| Soil pH | Neutral to slightly acidic |
| Bloom Time | Year-round with adequate light |
| Flower Colors | Red, pink, white, yellow |
| Hardiness Zones | 9–11 (USDA) |
| Native Region | Madagascar |
| Toxicity | Toxic to pets and humans (latex sap) |
Take Care of Crown of Thorns
Light Requirements
To keep your Crown of Thorns blooming, bright light is a must. Place it in a south- or west-facing window for at least 3–4 hours of direct sun daily. In low light, it will survive but may stop blooming.
You can move it outdoors in the summer—just avoid heavy rain and introduce it gradually to stronger sunlight.
Soil
Use a well-draining cactus or succulent mix. Add perlite or coarse sand for improved drainage. The roots are sensitive to excess moisture and will rot if left soggy.
Watering Schedule
This plant handles underwatering far better than overwatering.
- Spring–Fall: Water when the top inch of soil is dry.
- Winter dormancy: Reduce watering to once every 2–3 weeks.
Avoid splashing water on the leaves or stems to prevent fungal issues.
Temperature & Humidity
Crown of Thorns thrives in:
- 65–85°F (18–29°C)
- Can tolerate brief drops to 50°F (10°C), but no frost!
Humidity isn’t crucial—average home levels are perfect. Good air circulation helps prevent disease.
Feeding & Fertilizer
Fertilize lightly once a month during spring and summer using a balanced houseplant or cactus fertilizer. Stop feeding in the winter when growth slows.
Blooms
The bright “flowers” are actually colorful bracts, surrounding tiny actual flowers in the center. With enough sun and proper care, Crown of Thorns can bloom nearly year-round.
Want more flowers? More light = more blooms.
Pruning
Prune to shape or manage size in early spring:
- Use gloves—the sap is toxic and irritating.
- Cut just above leaf nodes to encourage bushier growth.
- Remove yellowing or dead stems as needed.
Propagation Tips
Euphorbia milii can be propagated by stem cuttings:
- Cut a 3–4 inch healthy stem with a sterile knife.
- Rinse off the sap, then let it dry for 2–3 days to callous.
- Plant in dry cactus mix and water sparingly after 5–7 days.
- Roots form in 3–4 weeks under warm, bright conditions.
Potting & Repotting
Use a heavy pot with a drainage hole—this plant can get top-heavy. Repot every 2–3 years in spring or when rootbound.
When repotting:
- Wear gloves.
- Handle the base carefully to avoid snapping brittle stems.
Overwintering
During the colder months:
- Keep in a sunny window.
- Reduce watering to once every few weeks.
- Stop fertilizing.
Watch for drafts—Crown of Thorns likes steady conditions and dry air.
Common Diseases and Problems
Common Pests & Diseases
| Problem | Symptoms | Solution |
|---|---|---|
| Mealybugs | White fuzz on stems/leaves | Dab with alcohol or spray insecticidal soap |
| Spider Mites | Fine webbing, yellowing leaves | Rinse off with water, use neem oil |
| Root Rot | Mushy stems, black base | Cut off affected parts, repot in dry mix |
Common Problems
- No Blooms: Not enough light
- Leaf Drop: Overwatering, cold drafts, or repotting shock
- Wilting: Underwatering or too much sun without acclimation
- Skin Contact Rash: Latex sap—always wear gloves when pruning
FAQs
Q: Is Euphorbia milii pet-safe?
A: No. The milky sap is toxic if ingested and irritating to skin.
Q: Can I grow this plant outside?
A: Yes, in warm zones (9–11). Otherwise, bring it indoors before temps drop below 50°F.
Q: How can I encourage more blooms?
A: Provide at least 4 hours of direct sunlight daily and fertilize monthly during the growing season.
The post Euphorbia milii (Crown of Thorns): How To Care For and Grow This Succulent appeared first on Smart Plants.
