Cotyledon ORBICULATA 'UNDULATA'

Cotyledon ORBICULATA 'UNDULATA' - Wavy-leaved pig's ear, White Lady, Cotyledon orbiculata 'Undulata'.

Cotyledon is a small genus of succulent shrubs in the stonecrop family (Crassulaceae), comprising about twenty species. All of them originate from arid regions of Africa - from South Africa, where most species are concentrated, to Ethiopia and the Arabian Peninsula, where they grow on rocky slopes, rock outcrops, and in dry scrub.

Members of the genus are low shrubs with brittle succulent shoots that lignify at the base over time. The root system is fibrous. Leaves are fleshy, opposite, sessile or on short petioles, each successive pair situated at a right angle to the preceding one; in a number of species, leaves are gathered into loose rosettes.

Peduncles rise from the tips of shoots or from the center of rosettes. The flowers are tubular-campanulate, nodding, gathered in loose umbel-like inflorescences, colored in orange, reddish, or salmon tones. The fruit is a follicle with numerous very small seeds.

Cotyledon orbiculata is a species originating from southern Africa, where it grows on dry rocky slopes and gravelly plains. A succulent shrub up to 1 m (3.3 ft) in height with erect or decumbent shoots. Leaves are large, up to 13 cm (5.1 in) long and 7 cm (2.8 in) wide, oval, grayish-green, covered with a dense white waxy coating that reflects sunlight and helps the plant retain moisture. The leaf margin is often colored reddish.

The cultivar 'Undulata' is distinguished by an expressive wavy leaf margin - it is this waviness that gave it its name. Flowering occurs in winter: nodding bell-shaped flowers of orange-red or salmon hues open on sturdy peduncles above the bush.

Cotyledon seeds are very small, almost dust-like, ripening in dry follicles. Soaking and rinsing such seeds is impractical - they easily get lost in liquid and damaged, so the substrate itself is disinfected: before sowing, it is drenched with a weak potassium permanganate solution and dried. Scarification and stratification are not required.

Sowing is conducted on the surface into a shallow container with sandy substrate - seeds are only lightly mixed with the top layer, without burying. The sowing is moistened with a spray bottle using a growth stimulant solution: SUPERthrive, HB-101, Aminozol, Epin, or Zircon, covered with glass or film or placed in a propagator, and germinated in the light at a temperature of 17-21 °C (63-70 °F). Sowings are ventilated daily; both waterlogging and drying out of the surface are unacceptable.

Under favorable conditions, initial sprouts appear after approximately 2 weeks; main germination usually takes 3-4 weeks, while individual seeds may delay longer. After emergence of sprouts, the cover is removed gradually. Pricking out is carried out after the formation of two to three true leaves; seedlings are carefully transplanted into individual pots while preserving the root ball.

Special notes: Seeds are very (!) small.

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Cotyledon prefers bright lighting and long daylength, but during midday hours in summer it is better shaded to avoid sunburn on the leaves. South- and east-facing windows are suitable. Under light deficiency, the plant stretches, pales, drops leaves, and ceases flowering.

Optimal summer temperature is 20-25 °C (68-77 °F); at this time the plant can be taken out to a balcony, terrace, or garden. In winter, a cool dormant period at 10-12 °C (50-54 °F) is needed - it is precisely what prepares the plant for prolonged flowering. Dry air is preferred, as in native habitats; only on the hottest days is light misting with warm water permissible, ensuring that water does not accumulate in rosettes.

Watering is carried out only after complete drying of the substrate. During a cool dormant period, watering is ceased completely; only upon severe loss of leaf turgor is the substrate lightly moistened. Consistently wet soil combined with low temperature quickly leads to rot and death of the plant. Water is taken at room temperature, settled or filtered.

A poor and loose substrate close to natural soil is composed: one part each of clay-sod soil, leaf mold, and washed coarse river sand, with the addition of zeolite, crushed charcoal, bone meal, and fine expanded clay. Prepared cactus substrate is also suitable. Repotting is carried out in spring by pot-transfer, renewing drainage; adult plants are potted on once every three years into a pot 2-3 cm (0.8-1.2 in) larger in diameter.

Fertilizer is applied only during active growth, once a month before flowering begins, following watering. Fertilizers are not used during the dormant period. Overfeeding is harmful to a succulent - the plant becomes overgrown, may drop leaves, and bloom sparsely.

The main pest of cotyledon is mealybug; an insecticide is used against it. The plant is rarely affected by diseases; problems arise only from care mistakes: under waterlogging, lack of light, and insufficient fresh air, shoot rot develops.