Euphorbia COERULESCENS

Euphorbia COERULESCENS - Blue euphorbia, Glaucous spurge, Euphorbia CAERULESCENS.

An original and unusual plant!

Euphorbia is one of the largest genera of flowering plants, belonging to the family Euphorbiaceae and comprising about 2000 species. They grow in the tropics and subtropics of all continents and amaze with the diversity of life forms: from annual herbs to shrubs and trees.

In succulent euphorbias, the stems are thickened, fleshy, often ribbed, sometimes spiny, and it is in them that water is stored, which makes the plants resistant to drought and irregular watering. Outwardly, many species resemble cacti, although they have no relationship to them. Leaves can be large or reduced, simple or lobed; in most succulent species they are small and quickly shed during the dry season.

A common feature of the entire genus is milky sap, poisonous in most species. The flowers are small and inconspicuous, gathered in special inflorescences - cyathia, surrounded by bracts that are often mistaken for petals. The fruit is a three-locular capsule with rounded or ovoid seeds.

Euphorbia coerulescens is a succulent shrub from the east of the Cape Province of South Africa. In nature, it is so common on the slopes of gorges and hilltops that an entire area was named after it - Noorsveld. The plant spreads by rhizomes and forms large continuous thickets.

The height reaches one and a half meters (5 ft), an adult bush carrying up to two dozen erect stems. The stems are up to 5 cm (2 in) across, with 4-6 ribs, dark green, with a glaucous waxy coating to which the species owes its name. There are no leaves; instead, paired dark brown spines up to 12 mm (0.47 in) long sit along the ribs, arranged in vertical strips.

Euphorbia seeds are rounded or ovoid, medium-sized, maturing in three-locular capsules that burst open upon ripening and scatter the seeds. Soaking them is impractical, so the substrate itself is sanitized: before sowing, it is drenched with a weak solution of potassium permanganate and dried slightly. Scarification and stratification are not required.

Sowing is carried out on the surface or with light burying, no more than 2 mm (0.08 in), into a loose sand-peat substrate. The sowing is moistened from a spray bottle with a growth stimulant solution: SUPERthrive, HB-101, Aminozol, Epin, or Zircon, placed in a greenhouse or covered with film, and germinated in the light, but not under direct rays, at a temperature of 21-25 °C (70-77 °F).

Under favorable conditions, the first seedlings appear within 12 days, the main germination is completed in 12-25 days, and individual seeds may delay longer than 40 days. To avoid stagnation of condensation, the container is aired 1-2 times a day for 10-15 minutes; both waterlogging and complete drying out of sowings are unacceptable. With the appearance of seedlings, the cover is gradually removed. Pricking out is carried out after the appearance of 2-3 true leaves, into individual small pots.

Special notes: The milky sap of euphorbia is poisonous and strongly irritates the skin and mucous membranes. All work with the plant is carried out wearing gloves; if sap gets into the eyes, they are immediately flushed with water.

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The plant prefers bright light and sunny windowsills, but also adapts to diffused light. With sufficient lighting, the coloration of the stems becomes richer, while in partial shade the euphorbia develops slowly, stretches, and loses its compact form.

In summer, the optimal temperature is 21-28 °C (70-82 °F), in winter 15-18 °C (59-64 °F), but not lower than 12 °C (54 °F). In cold weather, the plant needs a dormant period.

Watering is moderate, as the substrate dries out. In winter, watering is reduced to a minimum, just enough to prevent complete desiccation. Excess moisture causes rotting.

The substrate must be light and breathable, suitable for succulents: equal parts turf loam, leaf soil, coarse sand, and charcoal. A layer of drainage made of expanded clay or gravel is mandatory at the bottom of the pot.

Fertilizer is applied in spring and summer, once or twice a season, using succulent fertilizer. An excess of nitrogen is contraindicated: shoots stretch out and the plant loses its ornamental value.

Repotting is carried out in spring, once every 3-4 years, handling the root system with care. Pruning is needed only for sanitation, to remove damaged areas. In addition to seeds, euphorbia is propagated by cuttings, which are rooted after allowing the cut to dry - but working with them requires wearing gloves.