Light
These succulents require plenty of sunlight in order to thrive. A location that receives several hours of bright, direct light is best although they can tolerate medium light as well. Like many succulents, Euphorbia ingens cannot tolerate low light.
Soil
A sandy, well-draining soil mix is best for Euphorbia ingens. They are not picky when it comes to soil pH and grow readily in poor-quality soils. Choose a potting mix that is designed for cacti and succulents or mix your own at home using a 1:1 ratio of potting soil, perlite, and sand.
Water
Euphorbia ingens are accustomed to dry, arid conditions and can tolerate periods of drought. In fact, overwatering is one of the most common reasons that these succulents suffer when grown in garden beds or indoors as a houseplant. Ensure that you are letting the soil dry out between waterings and then water thoroughly. Providing your Euphorbia ingens with adequate drainage (in the form of soil and/or a container with drainage holes) is key to preventing overwatering.
Temperature and Humidity
Native to regions across Southern Africa, Euphorbia ingens prefer warm, dry conditions. This makes them particularly well-suited to indoor growing which has made them popular houseplants. Ideally, these plants should be kept in temperatures above 74 degrees Fahrenheit (23 degrees Celsius) but they can survive for short periods in temperatures as low as 28 degrees Fahrenheit (-2 degrees Celsius). Consequently, they can be grown outdoors year-round in USDA zones 10 through 11. Growers outside of these regions can grow Euphorbia ingens indoors year-round or in containers so that the plants can be overwintered indoors.
Fertilizer
These succulents are accustomed to growing in sandy, poor-quality soils and are not considered heavy feeders. In fact, over-fertilization can be a problem for Euphorbia ingens as they can easily suffer from fertilizer burn. If desired, a low-strength fertilizer designed for cacti and succulents can be applied in the spring and summer months to encourage strong, healthy growth although it is not necessary.
Propagating Euphorbia Ingens
While Euphorbia ingens can be grown from seed, the process can be tricky and seeds can be hard to come by. For that reason, these succulents are most commonly propagated by rooting stem cuttings which is far more reliable. Regularly taking cuttings from your plant will also encourage a fuller appearance as the stems will branch wherever they are pruned. Before you begin taking cuttings, it is important to take measures to protect yourself and your surroundings from the plant’s sap which can cause irritation if it comes into contact with the skin. Ensure that you use a pair of protective garden gloves and set something underneath your plant to protect the floor from dripping sap. To propagate Euphorbia ingens by stem cuttings, follow these steps.
Potting and Repotting Euphorbia Ingens
Euphorbia ingens should be repotted every couple of years in the spring or summer months. Roots growing from the pot’s drainage holes or circling the top of the pot are both indications that it is time to repot this succulent. Choose a pot that is a couple of inches larger than its previous container and ensure you have some fresh potting soil. Remove the plant from its pot and loosen the root ball slightly before placing it in its new pot. Add the fresh soil around the plant’s roots and pat it down firmly around the base of the plant to secure it in place. After repotting, return your Euphorbia ingens to its previous location and resume its regular watering schedule.
Common Pests and Plant Diseases
There are a few common pests and plant diseases to keep an eye out for when growing Euphorbia ingens. Most notably, these desert succulents are prone to root rot if they are overwatered or exposed to moist conditions for a prolonged period of time. Unfortunately, the early stages of root rot can be hard to detect in these cacti, and usually once it becomes clear that something is wrong it is too late to save the plant. The best way to protect against root rot is to ensure that your plant has plenty of sunlight and is drying out thoroughly between waterings. In addition to root rot, keep an eye out for common pests like mealybugs, spider mites, and aphids.
Common Problems With Euphorbia Ingens
For the most part Euphorbia ingens are fairly low-maintenance and problem-free. The most common issues encountered when growing these succulents usually arise from improper watering.
Yellowing Stems
Yellow stems are a sign that your Euphorbia ingens is underwatered. Gradually increasing the frequency of watering should help to resolve this issue and prevent further yellowing, although stems that are already yellow may not recover fully. Remember that these succulents usually need more frequent watering in the spring and summer than they do in the fall and winter. Don’t forget to adjust your watering accordingly.
Mushy Stems
A Euphorbia ingens with mushy stems almost certainly has root rot. It is important to act quickly as soon as you notice your plant has a mushy stem as root rot moves fast and can kill these succulents quickly. The best way to save a Euphorbia ingens that is suffering from root rot is to cut the stem off above the rot and root the cutting in fresh soil. Follow the propagation steps to root the stem cutting.
