Origin and Natural Habitat
Euphorbia aeruginosa is endemic to the Limpopo province of South Africa.
Plant Characteristics
Euphorbia aeruginosa is a shrub-forming species. It has blue-green stems with bright red spines, and forms yellow flowers in summer.
Care Guide
Light
This Euphorbia species prefers filtered sun. In cultivation, 40% shade cloth is recommended. This encourages stronger colouration and a more compact growth form while preventing sun damage. Do not plant in full shade.
Soil
Euphorbia aeruginosa prefers a gritty, inorganic soil medium that drains well, such as Ibaraki Akadama or Hyuga pumice.
Water
Euphorbia aeruginosa must only be watered in spring and summer. This plant should receive a thorough soaking of water every 7-10 days during the active growing season, but only if the soil is mostly dry. Keep dry in autumn and winter.
Pot size
This species should be grown in a container that is about 5cm wider than the base of its stem. When small, it can be grown in 10cm pots, but with time will need a larger pot. The stems elongated as they mature and form a medium-sized shrub.
Temperature
This species’ ideal temperature ranges between 20 – 30°C. It is quite adaptable and can tolerate 5 – 40°C. It is sensitive to frost and should be protected in winter.
Humidity
Euphorbia aeruginosa prefers dry conditions and should not be kept in areas with more than 50% humidity.
Fertilizing
Use a half-strength diluted general liquid fertilizer only during the growing season. Do not fertilize during winter. Alternatively, a small amount of slow-release fertilizer will be sufficient.
Growing season
Euphorbia aeruginosa grows actively in spring and summer, and their growth stops in autumn and winter.
Propagation
Euphorbia aeruginosa are best propagated from seeds or cuttings.
Stem propagation: Using a sharp, clean knife, cut one of the stems from the main stem. Let this dry for 10 days, then plant it.
Seed germination: Seeds should be sown in early spring. Plant them in a mix of coco peat and perlite, with some vermiculite, in an airtight container. Once most of the seeds have germinated, remove the lid of the container to allow airflow. Gently mist the seedlings every few days so that the soil does not dry out.