Last updated on August 25th, 2023 at 12:30 pm
Euphorbia dregeana, also known as the Drege’s euphorbia, looks similar to another member of the Euphorbia family, Euphorbia tirucalli.
Both plants have stems with milky sap that result from contact with the plant, as well as small flowers growing in clusters at the top of the stem and long spines at the base of each leaf.
The Euphorbia dregeana is a beautiful houseplant that not only looks great but also grows well in many different environments.
Origin and distribution
Euphorbia dregeana is a native to South Africa, growing in KwaZulu-Natal, Gauteng, and Mpumalanga. At altitudes between 950 and 2200 meters, it occurs in mountain grassland on rocky slopes. It also grows as a garden escapee in Lowveld gardens in KwaZulu-Natal where it is considered an invasive weed.
Other common names include the porcupine plant or devil’s backbone. The stem can grow up to 1 meter tall. It has three different types of leaves; the uppermost leaves are linear with spiny margins, the middle leaves are oblong with narrow spiny margins and the lowermost leaves are orbicular with entire margins.
The flowers have five white petals that can grow up to 12mm long. The plants have very small green fruits which turn brown when ripe and contain one seed each.
Euphorbia dregeana propagation
The easiest way to grow Euphorbia dregeana is to take a mature leaf cutting (at least 6 inches in length) that contains at least one node, or branch point. Stick it into your succulent soil mix.
As with many succulents, water generously when you take your cutting, then allow the soil to dry out between waterings. For propagation purposes, keep it in bright sunlight or under lights until new growth appears.
Once new growth appears, begin watering less frequently but more deeply. When the plant reaches about six inches tall, transplant it into a larger pot with cactus potting soil. It will tolerate full sun once established and grown for about three years.
After several years of growth, Euphorbia dregeana may become straggly-looking, at which time it should be pruned back by half. After pruning this species, give it a heavy dose of liquid fertilizer such as fish emulsion.
Although its white sap can cause an allergic reaction in some people, most enjoy its pretty flowers which appear during the late winter months.
Euphorbia dregeana care information
Euphorbia dregeana is a succulent that will do well in a bright location with temperatures above 60 degrees Fahrenheit (15.5 Celsius). The plant does not grow well under low-light conditions. To help encourage growth, cut back on watering your plant in the winter months. When it’s actively growing, increase water to two inches weekly.
Light requirement
Euphorbia dregeana likes a lot of light. While it can tolerate low light, it won’t be able to grow as fast or look as healthy. In order to keep your plant happy and healthy, make sure you place it somewhere with plenty of natural sunlight for at least 4 hours a day, more if possible.
But be careful not to put your plant in direct sunlight for more than 10 minutes a day or leave it out on a warm summer afternoon, its leaves will burn in direct sunlight!
Soil/potting mix
There are many different kinds of soil you can use to grow your Euphorbia dregeana. Some people prefer to use a cactus mix or sandy soil, while others find plain potting soil to be sufficient. Regardless of what you choose, try to make sure that your potting mix drains well.
You don’t want your plant’s roots sitting in soggy soil! To help with this drainage issue, feel free to add some sand to the bottom of the pot before adding the soil.
Watering
This succulent doesn’t need a lot of water, especially during its dormant period. Water it once every two weeks or so when you first get it home. When it begins to grow new growth, increases watering to once every seven days.
Decrease watering during dormancy in winter, but don’t completely stop. You can also mist the plant occasionally. Plant it outside for the summer months in an area with full sun and good drainage.
You can place it on your porch or balcony, but be sure that the container has holes to allow excess water to drain out.
Fertilizer
After planting, use a slow-release fertilizer that is suitable for succulents. A typical dose of fertilizer, like 16-16-8 would be applied about once a month during spring, summer, and fall.
Special care should be taken to avoid getting fertilizer on your plants’ leaves, as it can cause burns. If you must apply it, wear gloves when handling your new plants.
Keep in mind that overfertilizing will lead to brown spots on the plant, which may look like a disease but are actually just areas where the plant has been burned by too much fertilizer. When in doubt, less is more!
Temperature
As a succulent, Euphorbia dregeana appreciates warm temperatures. Though it grows in South Africa, where temperatures get as low as 10 degrees Celsius (50 degrees F), it prefers an average daily temperature of 21 degrees C (70 degrees F).
It can take hot weather during summer if you put it outdoors, but keep it out of direct sunlight to avoid sunburn. Indoors, place your plant in a sunny window with plenty of indirect light or under a grow light.
Humidity
Since they originate from a tropical climate, Euphorbias prefer moist environments. If you live in a dry area, you can assist with their water intake by grouping your plants together.
You can also mist them daily (in addition to regular watering) or place them in humid rooms like bathrooms or basements. If your plant is outside, move it into shade during hot months of summer or if there’s no breeze. Remember that too much humidity can be harmful as well, so don’t overdo it!
The ideal humidity range is 40-60%. If you feel the need to raise the humidity level of your home, install an ultrasonic mister. When using a space heater indoors, try placing one near your potted euphorbias so that they are close enough for some added warmth but not getting scorched by the heat.
Pruning
If your succulent is not growing as it should, you may need to prune it. When you prune a succulent that has been growing for more than one year, it’s important to remember not to remove more than a third of its stems or roots at once.
Trim back some of its oldest stems using sharp scissors and leave about two-thirds of them intact. Because these are older growths, they are stronger and can better withstand losing parts without becoming overly stressed by it.
It’s also wise to keep in mind the plant’s general shape when deciding which branches to cut off while avoiding any leafy new growths near the bottom if you want the plant to remain low-growing.
If your Euphorbia dregeana is small enough, you can clip off an entire shoot with just a pair of fingernail clippers and gently shake the leaves off it before planting it again in the soil.
The same thing applies to removing a large piece from the middle of the plant, first, take out a large branch (one-third) and then trim away smaller ones around it so that there is still plenty of foliage left.
When to repot
Repot your Euphorbia dregeana in spring before new growth emerges, or when roots fill the pot. Larger containers need to be re-potted more frequently. Check for adequate drainage by placing a few rocks at bottom of the container and checking if they get wet after watering.
If so, repot in a container just large enough for plant roots to fit snugly with a little room for air circulation, that is, no more than 2 inches from the sides of the container. Water frequently until established.
As the weather gets hotter and waterless. Feed monthly during the growing season with a liquid fertilizer diluted to half strength. In winter, feed every 6 weeks.
Fertilize sparingly during the fall months because the plant enters its dormant phase as it prepares for dormancy through the winter months of November through February (USDA zone 9).
Dormancy/Winter rest
During the winter months, Euphorbia dregeana plants are dormant. So don’t be alarmed if your plant looks like it is going to die. It’s not! It is just changing its cycle to survive colder temperatures. Your Euphorbia dregeana will not lose all of its leaves during dormancy.
You can cut back on watering so that the soil dries out between waterings. In the springtime, resume watering normally and fertilize with a slow-release fertilizer according to package instructions.
If you live in an area with cool winters, you may need to move your euphorbia indoors for the winter. If you have an extra room or basement that isn’t too cold (60°F), try placing it there for the duration of the winter season as long as there is good light available.
Euphorbia dregeana flower & fragrance
Euphorbia dregeana produces tiny yellow-green flowers that are not much to look at, but they give off a sweet fragrance that can attract bees.
Growth rate
Euphorbia dregeana is relatively slow-growing. Small plants can be kept indoors year-round in a shallow pot but will require repotting every 1-2 years as they outgrow their space. When planted outdoors, start with small transplants to allow room for growth.
Toxicity
Euphorbias dregeana is toxic to most animals, including dogs, cats, birds, horses, cattle, sheep, and goats. You’ll have to carefully consider where you plant it if you have livestock or pets.
USDA hardiness zones
Euphorbia dregeana thrives in USDA hardiness zones 8-11. In colder climates, grow it as a houseplant or in a large container to allow the soil to warm up. Grow the plant indoors near a window with filtered light.
If the plant begins to wilt, it may be due to overwatering or underwatering. Let the soil dry out before watering again.
Pests and diseases
Because of its succulent nature, Euphorbia dregeana is susceptible to pests like spider mites. If you see any webs on your plant or bugs crawling over it, spray with insecticidal soap or a water-and-soap mixture.
Keep up with these sprays throughout the summer months; spider mites can kill your plant if left untreated. Another common disease of the euphorbia is root rot from overwatering.
Avoid this by only watering once every couple of weeks and by using soil that drains well, such as cactus mix. When growing in containers make sure the pot has enough room for the roots to grow without getting cramped.
