The myrtle spurge (Euphorbia myrsinites) is a succulent species from Southeastern Europe into Western Asia. Its milky sap can induce irritation in the skin and eyes, and its effects are strongest in children. Extreme care should be taken when handling myrtle spurge. The effect is even such that many plants are unable to grow near the myrtle spurge.
I. Appearance and Characteristics
Euphorbia myrsinites, the myrtle spurge, blue spurge, or broad-leaved glaucous-spurge, is a succulent species of flowering plant in the spurge family Euphorbiaceae.
The plant is native to southeastern Europe and Asia Minor, from Italy east through the Balkans to Crimea and Turkey.
The specific epithet myrsinites is derived from the Greek word μυρσινίτης (myrsinites), which was used in Dioscorides’s De Materia Medica to describe its similarity to μυρσίνη (myrsine), aka myrtle (Myrtus communis).
Myrtle spurge is an evergreen perennial. It has sprawling stems growing to 20–40 cm long. The leaves are spirally arranged, fleshy, pale glaucous bluish-green, 1–2 cm long. The flowers are inconspicuous, but surrounded by bright sulphur-yellow bracts (tinged red in the cultivar ‘Washfield’); they are produced during the spring.
Plants spread primarily by seed and are capable of projecting seed up to 15 feet.
Toxicity
The plant’s milky sap can cause significant skin and eye irritation in humans and may cause blindness with contact with the eyes. The plant causes nausea, vomiting, and diarrhea when ingested. Goggles, gloves and protective gear is often used when removing plants. Children are more susceptible than adults to symptoms from myrtle spurge, suggesting play areas not in proximity to the species. Pets can have similar reactions to myrtle spurge sap exposure.
II. How to Grow and Care
Light and Temperature
This plant thrives to the fullest when planted under full sun. It can grow in USDA hardiness zones from 5 to 9. While it’s best grown outdoors, if you live in an area where the plant is an invasive noxious weed or in a colder climate, you can grow it indoors in a sunny south-facing window.
One of the reasons this plant is such an invasive noxious weed has to do with its ability to withstand temperatures that are very high (in the triple digits) or even very low (down to -20°F). There is no need to protect an established plant from climate extremes, but it does best in warm winter climates.
Water and Humidity
This succulent plant is drought tolerant. It needs minimal watering. Make sure that you don’t over-water your myrsinites as it will kill your plant. Water only when the soil is dry up to the length of your entire finger or in times of severe drought. Do not wet the leaves of the plant during watering, and water slowly and low in the morning when possible.
Soil
Your plant will easily grow in dry and hot areas that have poor soil. In fact, it prefers to grow in well-draining sandy or gravelly soil and is very tolerant of dry soil. Even pre-formulated cactus soil is too nutritious. If you’re working with that, add some coarse gravel or sand to give the mix even more drainage and sparser nutritive elements.
Fertilizing
For optimal care, fertilize myrtle spurge with a specific Succulents and Cacti Food during its growing season, spring to early fall. A quarterly application is adequate, following package instructions for dilution and volume. Fertilizing encourages robust health and vibrant growth. Use precautions to avoid over-fertilization, which can harm myrtle spurge’s delicate roots. During dormancy in winter, cease fertilization to allow myrtle spurge to rest.
Practical tip: Apply fertilizer to damp soil to prevent root burn and integrate into the soil evenly for maximum uptake.
Pruning
Euphorbia myrsinites pruning becomes a necessity if you want to counter their invasive nature. After blooming, in the spring and summer seasons, you can trim back your plant’s sprawling stems severely. At the very least, prune away spent flowers before they have a chance to release their seeds.
This will prevent your plant from rapidly spreading and flowering consistently. When a blooming stem of your myrsinites euphorbia starts to turn yellow, simply clip it off at the base with clean pruning shears.
Propagation
Since donkey tail spurges are invasive plant species, the plants spread primarily via their seeds. However, you can also propagate it via cuttings that will root easily in late spring and early summer during the growing season.
Remember to wear gloves, eye protection, and long sleeves to protect yourself from the saponin within the plant. Take a good-sized cutting, remove the bottom 2/3 of the leaves, and dip the tip in rooting hormone. Then place the cutting in coarse potting mix and wait. In 4 to 6 weeks, your cutting should be rooted.
Repotting
Repot your plant when it starts growing out of its existing container, find another container with adequate drainage holes that’s slightly larger than the one you’re working with. Remove the plant and soil from the pot, and add some coarse potting mix to the new container – enough to keep your plant at the level it was planted in the other pot. Then fill it in, and water lightly. Put it in full sun as it establishes new roots.
Transplanting
The prime time to transplant myrtle spurge is when spring is fresh or in full swing, offering stable, mild temperatures that encourage robust root growth. Select a sunny site with well-draining soil and gently settle myrtle spurge into its new home, keeping its unique growth pattern in mind.
Pests and Diseases
- Growing Problems
Your plant might spread and take over your entire garden if you don’t prune it in time. Prune right after it blooms to prevent it from self-propagating at a rapid pace. Also, make sure that you don’t over-water it, as soggy soil will kill your plant and create conditions where root rot can thrive.
- Common Pests
This plant is susceptible to pests such as aphids and mealybugs. You can blast either with a strong stream of water from a hose. For mealybugs, start by wiping them off the plant with a rubbing alcohol-treated cloth, then spray your plant with neem oil spray. As for aphids, make sure that your succulent is planted in well-drained soil. Allow your soil to dry between two rounds of watering.
- Common Diseases
When grown in moist conditions, your plant can suffer from bacterial and fungal rots, so make sure to plant it in medium-dry, well-drained soil. Root rot is a disease that is common with this plant in situations where the soil is too rich, you’ve fertilized, or the plant isn’t in a full sun location and the soil doesn’t dry between waterings.
To treat root rot, remove any damaged or diseased parts of your spurge. Then check the base of the plant. If it’s brown and mushy, you may need to get rid of it completely. If not, stop watering, or plant it in fresh, dry media. This may help remedy the issue.
III. Uses and Benefits
Euphorbia myrsinites is perfect addition to beds, borders, rock gardens or Mediterranean Gardens. Because of its low stature, it is great as a sprawling ground cover in the front of the border or as an edging plant. It could even be used alone in terracotta pots or as a trailer in mixed containers for its interesting blue foliage.