As a type of spurge, the Christ thorn develops a milky plant sap that serves as protection. Because of its toxicity, plant lovers are unsettled. If you pay attention to safe handling, you don't have to worry. The shrub will delight you with attractive flowers.
How do I properly care for a Christ thorn?
The Christ thorn (Euphorbia milii) is a succulent plant from Madagascar that is easy to care for and produces attractive flowers. As a type of milkweed, it contains poisonous plant sap, so care should be taken when handling it. The plant prefers sunny locations, permeable substrate and little water.
Origin
The Christ thorn has the Latin name Euphorbia milii. It belongs to the spurge genus and originally comes from Madagascar. Here the plant grows in highlands and coastal regions. It inhabits forests and grows on granite rocks. The plant was introduced to Europe in 1821. The German name refers to the thorny shoots that are reminiscent of Jesus' crown of thorns.
The plant has a very geographically isolated occurrence. Outside Madagascar, the Christ thorn is only widespread as an ornamental plant. For this reason it can be ruled out that the plant was used for the wreath of thorns. 2,000 years ago the shrub was still unknown in Asia Minor.
Growth
The plant grows as a succulent shrub. It forms thickened cell tissue in which it stores water. The leaves therefore feel fleshy. Thanks to this adaptation, the Christ thorn survives suboptimal conditions in which hardly any rain falls. The bush develops thorns on the shoots. They developed from leaves over the course of evolution and serve as protection against predators.
The shoots, like the leaves, are thickened and become woody over time. The shrub grows upright and hardly develops any branches. It grows up to 60 centimeters high.
leaves
Christ's thorns develop oppositely arranged leaves that sit between the thorns. Their shape is elongated to round. The leaves are light green in color and, like all parts of the plant, contain a milky sap that comes out at the base of the stem after being torn off. Avoid direct skin contact with the plant sap as it can cause irritation.
Bloom
The flowers of the Christ thorns are inconspicuous. The leaves, which have been converted into bracts, are strikingly colored. They appear reddish or white. Their shape is reminiscent of a kidney. They enclose the yellowish inflorescences, which consist of several branched stems. Each stem ends with a tiny flower.
The flowering period depended on the rainy and dry seasons of the original distribution areas. During dry periods the shrub goes dormant. It flowers in wetter conditions between January and March. From October to December it develops flowers for the second time, making it an ideal houseplant with a flowering period in winter.
Is Christ Thorn poisonous?
Like all spurge species, the Christ thorn produces a plant sap that contains toxic diterpene esters. These substances irritate the skin and activate sleeping cancer cells. If the skin comes into contact with the milk, the risk of skin cancer can increase. Particular caution is therefore required in households with children.
However, you do not have to ban the Christ thorn from your apartment as a houseplant. Wear gloves and avoid touching when repotting and pruning. The concentration of diterpene esters is particularly high in the hybrid Euphorbia x lomi and the related species Euphorbia leuconeura.
Symptoms of poisoning in animals:
- bloody diarrhea and vomiting, especially in dogs
- Colic
- Liver Damage
- Cramps and paralysis
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offshoot
Separated shoots of the Christ thorn develop roots within a short time. They are therefore ideal for propagation via offshoots. To do this, cut off shoots from the old plant. Make sure that the cutting is between eight and ten centimeters long. Use a clean and sharp knife to cut so as not to damage the plant. Dab the interface with kitchen paper. To stop the flow of milk, you can immerse the cutting in lukewarm water. Allow the interface of the cut shoot to dry before sticking it into the ground.
A mixture of cactus soil and sand is suitable as a substrate. It offers optimal permeability. In a warm place it takes about 30 days for the cuttings to develop roots. Cutting the top of the shoots encourages branching. This causes the cutting to grow bushier.read more
Which location is suitable?
Christmas thorns prefer a bright and sunny location. As succulent plants, they thrive in dry conditions, making the shrubs perfect houseplants. Especially in winter, the air in the room is very dry due to the constant heating, which does not harm the Christ thorn. It feels comfortable at temperatures between 18 and 24 degrees Celsius and prefers a place on the south window. In summer you can place the bucket in the garden. During the winter months, temperatures between ten and 15 degrees Celsius are ideal.
What soil does the plant need?
The succulent shrub prefers a well-drained substrate. A loose container plant soil is ideal. Cactus soil is an alternative. A high proportion of minerals in the substrate promotes he althy growth. Ideal conditions are provided by a pH value between 6.0 and 6.8.
The perfect mix:
- a part of humus-rich soil for optimal nutrient supply
- a part of loamy substrate as water storage
- 1, 5 parts quartz-containing sand as a mineral supplier
- 1, 5 parts gravel, expanded clay or lava granules for permeability
Multiply the thorn of Christ
Propagation is possible through cuttings and seeds. Offshoots are preferably taken from shoot tips in spring. The plant should be well developed so that it can subsequently regenerate. When you cut back the plant, cuttings are automatically created that you can grow. Be sure to wear gloves when cutting. The cuttings should be between eight and ten centimeters long. The longer you cut off the shoots, the more leaves the offshoot has available.
You can also propagate the Christ thorn using seeds that you can get from specialist retailers or collect from the plant yourself. Wait until the inflorescences have faded. They carry numerous brown to black seeds that you can remove by picking them apart. This propagation method is less promising than propagation by cuttings.read more
Sowing
Propagation by sowing is possible, but time-consuming. You can grow the seeds all year round using potting soil. Fill a planter with the substrate and distribute the seeds on top. They should only be lightly covered with soil and then slightly moistened. Cover the container with a transparent film. Place the pot in a warm and bright location where there is no direct sunlight.
To prevent mold from forming, you should remove the film for one to two hours every day. It takes about three to four weeks for the seeds to begin germinating. When the first shoot tips appear, remove the foil from the cultivation container. From a size of five centimeters, the young plants are placed in individual pots.
Cut the Christ thorn correctly
The succulent plant tolerates pruning well when fully grown. Pruning is rarely necessary because the plant has few branches and grows moderately quickly. Wear gloves for this care measure so that your skin does not come into contact with the plant sap. This way you also protect yourself from the thorns. If necessary, the shoots can be shortened all year round.read more
Water Christ Thorn
The Christ thorn has a low water requirement because it stores moisture in the thickened shoots and leaves. Before you water the plant, the substrate should dry on the surface. During the winter months you should reduce watering. The substrate may dry out, but should not be permanently dry. This lack of fluid encourages the shrub to go dormant over the winter. It sheds its leaves to save energy. Use lime-free water for watering. Rainwater at room temperature is ideal. Stale tap water can also be used.
Fertilize Christ Thorn properly
The growing season extends from May to September. During this time, the Christ thorn needs a nutrient supply every two to three weeks. Mix liquid fertilizer (€6.00 on Amazon) into the irrigation water. A cactus fertilizer is also suitable as a source of nutrients.
Repotting
As a slow-growing shrub, the Christ thorn takes up hardly any space. You can repot the plant into a larger container every two to three years. Choose a pot that is no more than two fingers larger than the old container. The ideal time for transplanting is in March, when the shrub awakens from its hibernation.read more
Wintering
There are no winter months in its original distribution area. Nevertheless, the plant withdraws and spends unfavorable periods in a dormant state. To promote he althy growth and abundant flower development, you should encourage this alternation of rest and activity. Winter is ideal for dry rest.
Reduce watering gradually. Only water enough to prevent the root ball from drying out completely. Pay attention to cool temperatures between ten and 15 degrees Celsius. These care measures lead to a slightly postponed flowering period, which you should take into account when purchasing. This is the only way to prevent the plant from developing unstable shoots and getting diseases.read more
Diseases
The Christ thorn proves to be a robust plant that is only affected by diseases and pests if the care is taken incorrectly. If the humidity is too high, the mildew fungus has optimal growth conditions. Mealybugs occasionally appear and settle on the shoots between the thorns and leaves. The milky sap it contains protects the bushes perfectly from animal pests, because the milk is also poisonous to most herbivores.
If the root ball is permanently in wet soil, rot can occur. If conditions do not improve quickly, the plant will die. A sudden change in temperature stresses the plant.read more
Yellow leaves
If the leaves turn yellow, the Christ's thorn no longer feels comfortable in its location. As a first aid measure, you should move the bush to another location to prevent leaf loss. Find a warm location with breezy conditions. A spot by the south window is ideal. In summer you can put the plant on the balcony. Make sure you have a location protected from the rain.
A change of location ensures better nutrient absorption, which means the plant gains resistance. It draws new energy, which prevents leaf loss. If the plant has already lost leaves, it will usually regenerate quickly under improved conditions. Also check the substrate conditions, because the plant must not be too moist.read more
Loses leaves
Christ Thorns prefer constant conditions. They react to fluctuations in temperature and humidity conditions by losing leaves. There is no need to worry about he alth status, because in most cases this process is normal. When plants go dormant during dry periods, they shed their leaves. Reduced watering units encourage the plant to lose leaves. A drop in temperature has the same effect, as this change also serves as an incentive for the start of the rest phase. The plant automatically develops new shoots and leaves when conditions improve again.
Caution is advised if the shrub loses leaves due to wet soil conditions. Too much moisture in the substrate causes the roots to rot. Because they are no longer able to draw nutrients and water from the soil, the bushes shed their leaves. Make sure that the root ball is only slightly moist, especially in winter. No water should remain in the saucer after watering.read more
Christ's thorn does not bloom
Flower development is favored by the alternation of dormant and growing periods. Reducing the duration of light stimulates the formation of flowers. Reduce light exposure by placing a cardboard box over the plant. The light duration should not exceed ten hours. In addition, you should reduce the amount of water during this time so that the plant goes into dry dormancy.
In September you can place the planter in a room that is not lit in the evening. The days are getting shorter and shorter and automatically give the Christ thorn an incentive to take a rest period. When the amount of light increases again, the bush forms fresh shoots and the flowers do not take long to develop.read more
Tip
You can rarely find Euphorbia milii in stores anymore. In most cases it is the hybrid Euphorbia x lomi. They are considered particularly attractive because of their compact growth habit and wide variety of colors. Note that these cultivars may contain higher concentrations of toxic diterpene esters.
Varieties
- Euphorbia x lomi: Hybrid between Euphorbia milii and Euphorbia lophogona. Develop thinner stems and thicker leaves than Euphorbia milii. Keep their leaves in winter. Blooms red, pink or yellow. Flowering period all year round. Compact growth.
- Euphorbia milii var. splendens: Blooms orange, pink, red or yellow. Up to two meters high.
- Euphorbia milii var. longifolia: Forms branches at the base. Branches up to two centimeters thick, limp.
- Euphorbia milii var. bevilaniensis: Inverted triangular leaves. Shoots up to five millimeters thick. Thorns up to one centimeter long.
