Is Crown of Thorns (Euphorbia milii) Poisonous? Can You Grow It Indoors? Growing Methods and Precautions
Crown of Thorns, also known as Iron Begonia, Qilin Thorn, and Qilin Flower, is a sprawling shrub plant. Crown of Thorns is a common plant for decorating the home. It is easy to care for, and in winter and spring it blooms with small flowers. Although the flowers are small, their colors are brilliant. Below, the editor will introduce the growing methods and precautions for Crown of Thorns.
Growing methods and precautions for Crown of Thorns
Potting soil: The leaf clusters of Crown of Thorns grow upright, so it is best to choose a relatively deep cylindrical pot, which will make it look compact and attractive. For the soil used for growing, you can use two parts garden soil and two parts river sand, one part compost, and mix in a small amount of horsetail bone meal and other materials as base fertilizer.
Temperature: The most suitable temperature for Crown of Thorns to grow is 15°C to 32°C. It is relatively afraid of high temperatures and muggy weather. If the summer temperature reaches above 33°C, it will enter a dormant state. In winter, temperature management for Crown of Thorns also needs to be strengthened, because when the temperature drops below 4°C it will enter dormancy, and when the temperature approaches 0°C it will freeze to death.
Light: Crown of Thorns is suitable for care in semi-shade, or provide 50% shade in sunlight, which is beneficial to the growth of its leaves and makes their color more attractive. In spring and autumn, direct sunlight can be given because the temperature is not very high. In winter, place it in a bright indoor location, while in summer, light needs to be controlled.
Fertilizer and water: Crown of Thorns has a particularly strong drought tolerance and is very suitable for growing in dry environments. Of course, Crown of Thorns still needs watering, but its root system is afraid of waterlogging. If water accumulates in the pot, or if it is watered and fertilized too frequently, it is prone to root rot.
Precautions
Crown of Thorns likes warmth and cannot tolerate cold. It grows best at around 22°C during the day and around 15°C at night. Kept at 15°C to 20°C in a greenhouse, it can bloom continuously all year. If the temperature drops to 10°C, it will shed its leaves and enter a semi-dormant state, then in the following spring produce new leaves and continue blooming. Crown of Thorns likes light. The more sufficient the sunlight before flowering, the brighter and more eye-catching the flowers, and the longer they last. With insufficient light, the flower color becomes dull, and if placed in shade for a long time, it will not bloom. Also be careful to maintain air circulation.
Crown of Thorns can be grown with cultured soil and horn hoof pieces as bottom fertilizer. During the growing period, fertilize once every half month, stop fertilizing after the Beginning of Autumn, and avoid fertilizers containing grease to prevent root rot. Crown of Thorns is drought-tolerant. In spring and autumn, watering should follow the principle of watering when dry and keeping it moist when wet. In summer, it can be watered once a day, and in the rainy season prevent waterlogging. In winter, do not water unless it is dry, and the pot should not remain moist for a long time. Watering should also be controlled during the flowering period, as too much water easily causes flower drop and root rot.
If you want Crown of Thorns to bloom more, you also need to pay attention to pruning. Wear gloves when pruning and cut off the stems of Crown of Thorns that have grown too long. This can promote branching, and Crown of Thorns will be able to grow more branches. Crown of Thorns only forms flower buds at the tips of the branches. If the stems grow too long, it will affect the ornamental value, and the plant shape will also become messy. At the same time, because it is covered with thorns and its sap is poisonous, sensitive skin can easily become itchy after contact. When caring for a potted Crown of Thorns, place it somewhere children cannot reach to avoid accidental injury.
Pruning methods and precautions for Crown of Thorns
Crown of Thorns blooms at the tips of new branches. If you want Crown of Thorns to bloom more, you must prune it properly. Because if the main branches are too long, there will be fewer flowers. Therefore, after the flowering period, the overly long and irregularly growing branches should be cut short. Generally, 2 new branches grow below the cut on the branch, and when the new branches grow to 5-6 cm, they can bloom.
Prune once a year. After a few years, the entire plant will be covered with bright small red flowers. Because the branches are slender, long, and relatively soft, as the plant grows, you can use bamboo sticks or wire to make supports of different shapes and tie the branches to them, making it form a flower column shape. When it blooms, it can better show the beauty of red flowers and green leaves. If it is not pruned in time and allowed to grow naturally, its main branches will grow longer and longer, not only blooming less but also making the plant shape unattractive.
Propagation methods and cutting time
The cutting medium is the nutrient soil, river sand, peat soil, or other materials used for cuttings. For home cuttings, due to limited conditions, it is difficult to obtain an ideal cutting medium. It is recommended to use a pre-mixed and sterilized cutting medium. Medium-coarse river sand can also be used, but it should be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkali areas; they are not suitable for the growth of flowering plants.
Crown of Thorns is mainly propagated by cuttings. Cuttings can be taken throughout the growing period, but May-June is best, with a high survival rate. Crown of Thorns is easiest to root from cuttings. Choose thick, strong branches about 10 cm to 15 cm long (they must have 3-4 leaf nodes), wipe away the white sap flowing from the cut, coat with plant ash, dry in a cool place for 2 to 3 days, and after the wound is dry, insert into plain sand. Water thoroughly, then water sparingly afterward, watering again only when the potting soil is slightly dry. After about 50 to 60 days, it can take root.
Is Crown of Thorns poisonous?
Crown of Thorns is a horticultural hybrid of Qilin Flower. Its entire plant is poisonous, and the white milky sap is highly toxic. Ingestion by mistake can cause vomiting and diarrhea. It is understood that Crown of Thorns is covered with “poison” all over. Crown of Thorns releases an irritating and unpleasant odor, and the soil in which this type of plant has been grown has been detected to contain cancer viruses and activating substances for chemical carcinogens. Therefore, it is not suitable for indoor cultivation.
Reasons for yellowing leaves of Crown of Thorns
1. Too much watering: Crown of Thorns has fleshy stems and leaves. It is not afraid of drought, but afraid of waterlogging. Too much watering will damage the root system and cause leaves to turn yellow and fall off.
2. Too much fertilizer: Crown of Thorns does not like fertilizer. During cultivation, if too much fertilizer is applied or unfermented raw fertilizer is used, it will burn the root system and cause leaves to turn yellow.
3. Poor air: Crown of Thorns has certain requirements for its surrounding growing environment and is most suitable for ventilated and breathable places, so it is generally planted more in courtyards and balconies. If indoor ventilation is poor and it is relatively stuffy and hot, it will cause Crown of Thorns leaves to turn yellow.
4. Chemical damage: When watering Crown of Thorns, if tap water is used, let it sit for a few days first. Otherwise, the chloride in the water is toxic to the plant, causing Crown of Thorns leaves to turn yellow and fall off.
5. Winter dormancy: In late autumn, while Crown of Thorns enters its full flowering period, it is also about to enter the winter dormant period, so yellowing leaves are normal. Even if all the leaves fall off, new leaves will sprout again in spring.
6. Temperature too low: In areas where the winter temperature is below 10°C, the old leaves of Crown of Thorns will fall off, leaving only the tender leaves at the top. When the temperature is even lower, the leaves will all dry up and fall off.
What to do if Crown of Thorns leaves turn yellow
If there is too much watering, reduce watering and move it to a place with sufficient sunlight. If it is caused by too much fertilizer, fertilize appropriately, and before fertilizing check and understand whether the fertilizer is suitable for the growth of Crown of Thorns. As much as possible, do not place Crown of Thorns in a relatively stuffy and unventilated place. It is best to plant it in a courtyard. After all, Crown of Thorns has a certain toxicity, and for safety reasons it is also not suitable to place indoors.
In addition, Crown of Thorns is easy to cultivate, and generally pest and disease problems rarely occur. It also has elegant flowers and a long flowering period, making it one of people's favorite decorative plants. However, Crown of Thorns has thorns, so be careful not to get pricked. If it is caused by too low a temperature, the amount of direct sunlight for Crown of Thorns should be increased.