The Crown of Thorns plant, also known as Euphorbia milii, is a popular houseplant that is loved for its unique appearance and hardiness. However, despite its popularity, the plant does come with some notable disadvantages that gardeners should be aware of before growing it.
Growth Speed
One disadvantage of the Crown of Thorns plant is that it is a very slow grower. The plant only gains about 1-2 inches in height each year, which means it can take many years for a small plant to reach maturity and flower. For those looking for quick growth in their houseplants, the Crown of Thorns is not a good choice.
Spines
The Crown of Thorns gets its common name from the sharp spines that densely cover its stems and branches. These spines can grow up to 2 inches long and are notoriously sharp. Working with and handling these plants requires thick gloves to avoid painful puncture wounds from the spines.
The spines can also pose safety issues if the plant is kept in a home with children or pets, who may accidentally brush up against the sharp spines and get injured. Placement out of reach is necessary in these cases.
Toxicity
All parts of the Crown of Thorns contain toxic compounds called diterpenoid euphorbol esters. If ingested, these compounds can cause vomiting, diarrhea, and irritation or swelling of the mouth and throat. Pets or small children sometimes try to sample houseplants out of curiosity, so extra care must be taken with toxic plants like the Crown of Thorns.
The sap from broken stems or leaves can also cause skin rashes or irritation if handled frequently or in large amounts. Wearing gloves when pruning or propagating the plant is recommended.
Sensitive to Temperature Changes
The Crown of Thorns prefers warm temperatures between 65-85°F and does poorly if exposed to sudden drops or plunges in temperature. Exposure to temperatures approaching freezing can severely damage the plant. This sensitivity makes it a bit tricky to grow in climates that get very cold in winter.
Additionally, cold drafts from windows or doors can cause leaf drop. Finding a stable, warm spot protected from cold is key to avoiding damage.
Prone to Mealybugs
Mealybugs are common pests that can infest houseplants like the Crown of Thorns. These small, sap-sucking insects create cottony masses on stems and leaves while feeding on plant fluids. An infestation can result in yellowing, wilting, and loss of leaves or stems.
The dense, shrubby growth of the Crown of Thorns provides the perfect hiding spot for mealybugs, making infestations more difficult to control. Careful monitoring and early treatment of any pests is crucial.
Sensitive to Overwatering
The Crown of Thorns naturally grows in hot, very dry desert environments. As a result, it strongly dislikes too much moisture around its roots and can quickly suffer from root rot if overwatered. Watering must be done carefully and infrequently to avoid problems.
The dense, spiny growth makes it difficult to tell when the soil is dry. It’s better to underwater than overwater this species. Allowing the soil to fully dry out between waterings is the safest approach.
Difficult Propagation
Trying to propagate from stem cuttings or leaves can be frustrating with the Crown of Thorns. The stems often rot before they can produce roots due to the plant’s sensitivity to moisture. And leaves can be difficult to successfully root.
Some gardeners have success with stem cuttings if the cut end is allowed to harden off and dry for a few days before planting. But overall, propagation is challenging with this species.
Leggy Growth
Without proper light levels, the Crown of Thorns grows in a leggy, loose, unattractive manner. The stems elongate and become floppy and sparse. To keep the plant full and compact, very bright light is required.
Supplementing with grow lights or rotating the plant frequently may be necessary in winter or low light conditions. Pruning periodically can also encourage bushier regrowth.
Potential for Light Sensitivity
Some gardeners report that intense direct light can burn the leaves of their Crown of Thorns, causing brown crispy spots. This seems to be an issue primarily when moving the plant from indoor conditions to direct outdoor sunlight.
Gradual acclimation by increasing light levels slowly over a week or two is recommended to avoid light damage. Keeping the plant permanently in bright indoor light rather than full sun may prevent problems.
Difficulty Finding Perfect Watering Schedule
Determining just how frequently to water the Crown of Thorns can be a struggle for some gardeners. Going too long between waterings risks drying out or dropping leaves and buds. But overwatering causes rapid root rot.
There is no set timeline for watering – many factors like container size, soil type, humidity, and warmth impact soil drying time. Monitoring for soil dryness and understanding the plant’s signs of thirst takes trial and error.
Vulnerable to Root Rot
As mentioned, overwatering is the fastest way to kill a Crown of Thorns. Prolonged wet soil leads to fungal root rot diseases that damage or kill the root system. Once rot takes hold, the chances of saving the plant drop significantly.
Careful attention to watering technique, soil amendments to improve drainage, and potting in terracotta rather than plastic containers can help reduce the risk of root rot in this moisture-sensitive species.
Conclusion
The Crown of Thorns makes a unique addition to indoor plant collections. But like all plants, it comes with certain care requirements and disadvantages. Its painfully sharp spines, toxicity, pest and disease susceptibility, and watering needs require research and special handling.
Weighing the beautiful flowers and unusual appearance against the potential challenges can help determine if this risky but rewarding plant is a good match for your gardening abilities and household safety.
| Disadvantage | Description |
|---|---|
| Slow growth | Only gains 1-2 inches per year |
| Sharp spines | Spines can grow up to 2 inches long and require thick gloves when handling |
| Toxicity | Contains toxic compounds that can cause vomiting, diarrhea if ingested |
| Temperature sensitivity | Does poorly if exposed to sudden drops in temperature or cold drafts |
| Prone to mealybugs | Mealybug infestations can damage leaves and stems |
| Overwatering sensitivity | Wet soil leads to root rot – requires careful, infrequent watering |
| Difficult propagation | Cuttings and leaves often rot before rooting |
| Leggy growth | Needs very bright light to avoid lanky, loose growth |
| Potential light sensitivity | Direct sun can possibly burn leaves |
| Watering challenges | Difficult to determine perfect watering frequency |
| Vulnerability to root rot | Wet soil quickly causes root rot that can kill the plant |
Other Care Challenges
In addition to the key disadvantages already covered, the Crown of Thorns has some other care requirements that add to its difficulty level as a houseplant.
Fertilizer Needs
This plant is a light feeder that requires careful fertilization. Using a balanced liquid fertilizer diluted to half strength every 2-4 weeks during the growing season is recommended. Going overboard with fertilizer can damage the roots or leaves.
Repotting Difficulty
Those large, sharp spines make repotting a challenge. Thick gloves and caution are a must. The plant’s sensitivity to root disturbance also means repotting should only be done when truly necessary, as it can set back growth.
Slow to Recover from Stress
Bouncing back from any adverse conditions like under watering, temperature extremes, or repotting shock can take time. Having patience through stress periods is important, as the plant may lose leaves or go dormant for a while.
Moderate Humidity Preferences
While not a jungle plant, the Crown of Thorns prefers a minimum of 40% humidity to remain healthy. This can require humidifier use in very dry indoor conditions. Low humidity causes leaf browning and drop.
Cautious Pruning
Pruning not only requires dealing with painful spines, but should also be kept minimal. Removing more than 1/3 of the plant at once can set it back. Prune sparingly just to shape as desired.
Slow Flowering Process
The coveted flowers take time and maturity to develop. The plant may not bloom until 3-5 years old. Even then, the flowering period only lasts up to 3-4 weeks. Patience is required to enjoy the flowers.
Alternatives to Consider
If the disadvantages and picky care needs of the Crown of Thorns seem too daunting, here are some alternative plants to consider that have lower maintenance needs:
Ponytail Palm
With a similar unique shape but no spines or toxicity, the ponytail palm is an easier-care option. It requires similar dry, warm conditions but is faster growing and more forgiving.
Paddle Plant
Also known as flapjacks, paddle plants have round, flattened paddles for leaves. They thrive in arid conditions like the Crown of Thorns but have no spines. Their growth is slow but steady.
Parsley
A culinary herb, parsley thrives in average indoor conditions with moderate watering and fertilizing. Its bright green leaves provide lovely texture without spines or toxicity.
Peperomia
With hundreds of varieties, Peperomia offers easy-care texture from bumpy leaf shapes. Water when soil is partly dry and provide moderate light. Minimal effort yields a cute houseplant.
Aloe Vera
For hardy texture with less pain, aloe vera has thick, spiny-edged leaves but minimal sharpness. It adapts easily to arid homes and requires little care once established.
Conclusion
The Crown of Thorns succulent provides unique visual appeal with its dense spiny growth and showy flowers. However, its care difficulties, toxicity, slow growth, and sensitivity to watering issues present challenges to success with this houseplant. Weighing its pros, cons and specific needs against your own abilities can determine if it’s the right choice for your home.
