Crassula perforata is one of the most visually distinctive and widely cultivated species in the genus Crassula. Known universally as the string of buttons — and also as the necklace vine, pagoda plant, or sosatieplakkie in Afrikaans — this small, scrambling succulent is instantly recognisable by its triangular, grey-green leaves that are fused in pairs at the base and stacked along the stem in a tightly geometric spiral, creating the illusion of threaded beads or stacked buttons on a skewer. Its compact, architectural growth, ease of propagation, and suitability for hanging baskets and mixed succulent arrangements have made it one of the most shared and photographed Crassula species on social media, and a staple of the contemporary indoor plant aesthetic.
Taxonomy and Naming History
Crassula perforata was first described by the Swedish botanist Carl Peter Thunberg in 1778, in the Nova Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum, based on specimens collected in South Africa. The accepted name is Crassula perforata Thunb.
The species has accumulated a number of synonyms over the past two and a half centuries, the most notable being:
- Crassula perfossa Lam. (1786)
- Crassula connata Donn (1804)
- Crassula anthurus E.Mey. ex Harv. (1862)
- Crassula conjuncta N.E.Br.
- Crassula coronata Heynh.
- Crassula perfilata Scop.
POWO recognises two subspecies: Crassula perforata subsp. perforata and Crassula perforata subsp. kougaensis van Jaarsv. & A.E.van Wyk, the latter described in 2009 from the Kouga region of the Southern Cape and characterised by smaller, narrower leaves with more pronounced red margins and a more compact, dense growth habit.
Etymology
The genus name Crassula comes from the Latin crassus (“thick, fat”), referring to the succulent foliage of the genus. The specific epithet perforata derives from the Latin perforatus (“pierced, perforated”), describing the way the leaves, fused at the base around the stem, create the visual impression that the stem has been threaded through perforations in each leaf pair — as if a wire had been pushed through a stack of buttons.
The common name “string of buttons” is a direct metaphor for this stacked appearance. “Necklace vine” evokes the ornamental, trailing habit of mature plants. The Afrikaans name sosatieplakkie compares the leaf arrangement to chunks of meat and vegetables threaded onto a sosatie (kebab) skewer — an appealingly local description.
Natural Habitat and Distribution
Crassula perforata subsp. perforata is native to South Africa, ranging from the Western Cape (near Worcester) through the Eastern Cape to central KwaZulu-Natal. It occurs in subtropical thicket vegetation and on rocky slopes, typically in sheltered positions among boulders, in rock crevices, and in the understory of dry scrub, where it scrambles through and over neighbouring shrubs. Altitudes range from near sea level to approximately 1,000 m.
Crassula perforata subsp. kougaensis is restricted to the Kouga region of the Southern Cape Province.
Climate across the natural range
The species’ distribution spans the transition zone between the winter-rainfall Western Cape and the summer-rainfall eastern regions, meaning it experiences a mixed rainfall regime over much of its range. In the western parts (Worcester area), rainfall is predominantly winter-driven, with 250–400 mm annually and hot, dry summers. Through the Eastern Cape, rainfall becomes more evenly distributed or bimodal (spring and autumn peaks), with annual totals of 400–700 mm. In KwaZulu-Natal, summer rainfall dominates, with higher annual totals approaching 700–900 mm.
Temperatures across the range are warm-temperate to subtropical. Summer maxima commonly reach 28–35 °C; winter minima fall to 2–8 °C depending on altitude and distance from the coast. Light frost occurs in the inland parts of the range, but the species generally occupies sheltered, frost-protected microsites (rock crevices, cliff bases, thicket understory) rather than exposed hilltops. The combination of shelter, rocky substrates with excellent drainage, and moderate to low rainfall defines its ecological niche: Crassula perforata is a semi-shade-tolerant scrambler of rocky, well-drained habitats, not an open-ground xerophyte.
Botanical Description
Growth habit and stem
Crassula perforata is a small, scrambling to semi-prostrate succulent subshrub. Stems emerge from a prostrate base and develop upright or arching secondary branches, reaching 30 to 60 cm in length. Initially erect, the stems gradually become sprawling and pendant as they elongate, which makes the plant naturally suited to hanging containers and elevated displays. Stems are thin (3–5 mm diameter), somewhat woody at the base, and branch freely, readily forming dense, attractive clumps over time.
Leaves
The leaves are the defining ornamental feature. They are opposite, decussate (each pair at right angles to the previous pair), triangular to broadly ovate, 15–25 mm long, thick and fleshy, with a flat to slightly concave upper surface. Each pair is fused at the base, encircling the stem — the “perforated” effect that gives the species its name. The leaf colour is grey-green to blue-green, often with a subtle glaucous bloom, and the margins develop a conspicuous reddish to pinkish-red edge under stress conditions (strong light, water restriction, cool temperatures). This red marginal colour is one of the plant’s most attractive features and intensifies markedly in bright, direct light.
The leaves are arranged in a tightly stacked spiral along the stem, with very short internodes in compact conditions. The overall effect is geometric and orderly — a quality that appeals strongly to design-conscious plant enthusiasts and photographers. Under low light, internodes elongate and the stacked effect loosens, producing a leggier, less photogenic plant.
Flowers and pollination
The inflorescence is a long, slender thyrse (15–30 cm), bearing numerous tiny, star-shaped, cream to pale yellow flowers. Flowering occurs in spring and summer (November to April in the Southern Hemisphere; May to October in the Northern Hemisphere). The inflorescence type is a key diagnostic character distinguishing Crassula perforata from its close relative Crassula rupestris, which produces a shorter, rounded, dense inflorescence with leaf-like bracts at the base and flowers in winter. Pollinators include butterflies, small bees, and flies.
Root system
The root system is shallow and fibrous, consistent with the species’ habit of growing in thin, rocky soils and crevices. Adventitious roots form readily at stem nodes, especially where the stem contacts soil or moist surfaces — a trait that facilitates both natural vegetative spread and propagation in cultivation.
Crassula perforata vs Crassula rupestris — How to Tell Them Apart
Crassula perforata and Crassula rupestris are frequently confused because both are stacked-leaf, scrambling species with a similar overall appearance. The key differences are:
Inflorescence. Crassula perforata produces a long, open, elongated thyrse (15–30 cm). Crassula rupestris produces a short, compact, rounded inflorescence with conspicuous leaf-like bracts at the base.
Flowering time. Crassula perforata flowers in spring and summer (November–April in South Africa). Crassula rupestris flowers in winter (June–October).
Leaf shape. Crassula perforata tends to have slightly more triangular, flatter leaves. Crassula rupestris leaves are typically rounder, more convex, and often more compact.
Stem habit. Crassula perforata produces longer, more rambling stems that become trailing. Crassula rupestris is generally more compact and upright, particularly the subspecies marnierana (commonly sold as “Jade Necklace”).
Popular Cultivars and Forms
Crassula perforata f. variegata — the most widely available cultivar. The leaves are striped in cream-yellow and green, with pink-red margins that become vivid in strong light. The variegation fades on older leaves, with the brightest colouration on new growth. This form is slower-growing than the type species due to reduced chlorophyll. It requires bright, indirect light to maintain variegation without leaf scorch and is slightly more susceptible to overwatering and rot.
Crassula perforata ‘Giant Form’ — a larger-leaved selection occasionally encountered in specialist collections. Leaves can exceed 30 mm in length. Relatively uncommon in the trade.
Note on trade confusion. Several other stacked-leaf Crassula species and hybrids circulate under similar common names (pagoda plant, string of buttons, jade necklace). In particular, Crassula rupestris subsp. marnierana is frequently mislabelled as Crassula perforata in retail. The inflorescence and flowering season remain the most reliable identification characters for differentiation.
Cultivation Guide
Light requirements
Crassula perforata performs best in bright, indirect light with some direct sun — ideally morning sun or late afternoon sun, with protection from the most intense midday summer heat. In its natural habitat, it often grows in the partial shade of boulders and other shrubs rather than in full, unfiltered exposure. This makes it somewhat more shade-tolerant than Crassula arborescens or even Crassula ovata, though it still needs good light to maintain its compact, stacked form and vivid red-margined colouration.
Insufficient light causes rapid etiolation: the internodes elongate, the leaves spread apart, and the tight stacked aesthetic is lost. Full shade is not tolerated. Indoors, an east-facing or bright north-facing window (in the Northern Hemisphere) is ideal. If the only available position is a south or west window, provide some diffusion during the hottest hours in summer to prevent leaf scorch, particularly for the variegated form.
Temperature and hardiness
Crassula perforata is rated for USDA hardiness zones 9b to 11b. It tolerates brief frost down to approximately –2 °C to –3 °C when the substrate is dry, though leaf damage and tip dieback are common at these temperatures. Sustained freezing is fatal. In maritime Mediterranean climates (Côte d’Azur, coastal California, coastal Portugal), it can be grown outdoors year-round in sheltered, well-drained positions. In colder climates, it is best treated as a seasonal outdoor plant or a permanent indoor/greenhouse subject.
Ideal growing temperatures are 18–28 °C. The species handles summer heat up to 35 °C with adequate airflow but does not appreciate sustained temperatures above 38 °C. A cool winter rest at 8–12 °C with reduced watering promotes compact growth and flowering.
Substrate
A very well-draining mineral-rich mix is essential. The species is particularly prone to stem rot at the base if moisture stagnates around the lower stem nodes. A mix of 50–60% mineral (pumice, perlite, coarse grit) with 40–50% quality potting compost works well. Alternatively, a standard commercial cactus mix amended with extra perlite or pumice is satisfactory. Shallow, wide pots and terracotta containers are preferred to promote rapid drying of the substrate between waterings.
Watering
Water moderately during the growing season (spring through autumn), allowing the substrate to dry out between waterings. The species’ thin stems and relatively small root system make it less drought-tolerant than tree-forming Crassula species like Crassula ovata or Crassula arborescens: prolonged drought causes the lower leaves to shrivel, dry, and drop. However, overwatering is far more dangerous than underwatering — base rot develops quickly in consistently moist conditions. Aim for a regular cycle of thorough watering followed by near-complete drying, with progressively longer intervals in winter.
Fertilising
Feed sparingly. A dilute balanced liquid fertiliser at half strength, applied once a month from mid-spring to early autumn, is sufficient. No fertiliser in winter. Over-fertilising promotes soft, leggy growth.
Repotting
Repot every two to three years in spring, or when the plant has outgrown its container. Crassula perforata clumps readily, and a single plant can fill a wide, shallow pot within a few growing seasons. When repotting, handle carefully — the stems are somewhat brittle and snap easily at the nodes. This is not a disaster, as the detached segments root readily, but it can be frustrating if the goal is to maintain an intact specimen.
Pruning and display
The trailing, scrambling habit of Crassula perforata lends itself to several display styles. In a hanging basket or elevated pot, the stems cascade attractively. In a mixed succulent arrangement or terrarium-style planter, the plant threads through neighbours in an appealing, informal way. Pinch or cut back stems that become excessively long or leggy to promote branching and maintain density. Pruned cuttings are easily propagated.
Propagation
Crassula perforata is exceptionally easy to propagate — one of the simplest succulents to multiply.
Stem cuttings — the primary method. Take a stem cutting of 5–10 cm, remove the lower one or two leaf pairs, allow the cut to callus for one to three days, and insert into slightly moist, well-draining substrate. Roots develop within one to three weeks, and new growth follows shortly after. Success rates are very high even for beginners. Spring and summer are optimal, but cuttings taken at almost any time of year will root in warm conditions.
Leaf cuttings — possible but less reliable and much slower than stem cuttings. Carefully detach a complete leaf pair (ensuring the base is intact), allow it to callus, and place on the surface of dry succulent mix. Small plantlets may emerge in three to six weeks, though the success rate is lower than with stem cuttings.
Division — mature clumps can be divided at repotting time. Simply separate rooted sections and pot them individually.
In nature, the species spreads vegetatively with ease. Stem segments that break off and fall among rocks or onto soil root at the nodes and establish new colonies. This is reflected in the dense, clumping populations observed across its range.
Pests, Diseases, and Common Problems
Stem and root rot — the most common problem. The thin stems are especially vulnerable to rot at the base and at stem nodes in contact with persistently moist substrate. Symptoms include soft, translucent, darkened tissue at the stem base and a mushy texture. Treatment: cut above the rot into healthy tissue, allow the cutting to callus, and re-root in fresh, dry substrate. Prevention: improve drainage, reduce watering frequency, ensure good airflow around the base of the plant.
Mealybugs — the most frequent pest. They colonise the tight spaces between stacked leaf pairs, where they are well hidden and difficult to reach. Treat with isopropyl alcohol on a fine-tipped brush or cotton bud. For severe infestations, a systemic insecticide may be necessary because the stacked leaf architecture provides significant physical protection to the insects.
Scale insects — less common than mealybugs but can affect stems. Remove manually with alcohol swabs.
Etiolation — insufficient light causes elongated internodes and loss of the compact stacked form. The only remedy is to provide more light. If the plant has already etiolated, cut back to a compact section and provide brighter conditions for the regrowth.
Lower leaf drop — normal as the plant matures. The lowest leaf pairs on older stems dry and fall off naturally, exposing the woody stem base. This is not a disease — it is the species’ natural growth pattern as a scrambling subshrub.
Toxicity
Like other Crassula species, Crassula perforata is listed as toxic to cats, dogs, and horses by the ASPCA. The suspected toxic compounds are bufadienolides (cardiac glycosides). Ingestion may cause vomiting, lethargy, and loss of coordination. In humans, the plant is not considered seriously toxic, though the sap may cause mild skin irritation in sensitive individuals. Keep out of reach of curious pets, particularly cats, which may be attracted to the trailing stems.
Frequently Asked Questions
How do I tell Crassula perforata apart from Crassula rupestris?
The most reliable difference is the inflorescence. Crassula perforata produces a long, open, elongated flower cluster (15–30 cm) and blooms in spring and summer. Crassula rupestris produces a short, dense, rounded flower cluster with leaf-like bracts at the base and blooms in winter. Without flowers, Crassula perforata tends to have longer, more trailing stems with slightly more triangular, flatter leaves, while Crassula rupestris is more compact and upright with rounder leaves.
Why is my string of buttons getting leggy?
Leggy growth (elongated internodes, loose stacking) is almost always caused by insufficient light. Crassula perforata needs bright light with some direct sun to maintain its tight, compact stacked form. Move the plant to a brighter position, cut back the leggy stems, and the new growth should emerge compact. The old leggy sections will not re-compact, so pruning and re-rooting is the most effective correction.
Can I grow Crassula perforata in a hanging basket?
Yes — it is one of the best succulent species for hanging displays. The stems naturally trail and cascade as they elongate, creating a very attractive curtain effect. Use a well-draining substrate, a container with drainage holes, and position the basket in bright, indirect light with some direct sun. Water thoroughly but infrequently, and ensure excess water drains completely — water pooling in the base of a basket is a recipe for rot.
Is the string of buttons toxic to cats?
Yes. The ASPCA lists Crassula species as toxic to cats, dogs, and horses. Ingestion can cause vomiting, lethargy, and loss of coordination. The trailing stems can be particularly tempting for cats to bat and chew. If you have curious pets, consider placing the plant in a high hanging basket completely out of reach, or choose pet-safe alternatives like Haworthia or Sedum morganianum.
How do I get more red colour on the leaf edges?
The red-pink marginal colouration is a stress response triggered by bright direct light, moderate water restriction, and cool temperatures. To intensify the colour, provide several hours of direct morning or late afternoon sun, water slightly less frequently than usual (allowing the substrate to stay dry a little longer between waterings), and expose the plant to cooler night temperatures (10–15 °C) in autumn and winter. Plants grown in shade with regular watering remain uniformly green.
Why are the lower leaves on my Crassula perforata drying up and falling off?
Gradual loss of the lowest leaf pairs is normal for this species. As the stems elongate, the oldest leaves at the base dry out and drop, leaving the woody stem exposed. This is the natural growth pattern of a scrambling subshrub, not a sign of disease. If leaf loss is rapid, widespread (not just at the base), and accompanied by soft or discoloured tissue, suspect overwatering or root rot rather than normal ageing.
Sources and Further Reading
- Plants of the World Online (POWO), Royal Botanic Gardens, Kew — Crassula perforata Thunb. powo.science.kew.org
- Tölken, H.R. (1985). Crassulaceae. In: Leistner, O.A. (ed.), Flora of Southern Africa, Vol. 14. Botanical Research Institute, Pretoria.
- Van Jaarsveld, E.J. & Van Wyk, A.E. (2009). Crassula perforata subsp. kougaensis, a new subspecies from the Southern Cape. Aloe, 46(1): 22–23.
- Eggli, U. (ed.) (2003). Illustrated Handbook of Succulent Plants: Crassulaceae. Springer, Berlin.
- Rowley, G.D. (2003). Crassula: A Grower’s Guide. Cactus & Co. Libri, Venegono Superiore.
- Court, D. (2010). Succulent Flora of Southern Africa. 3rd edition. Struik Nature, Cape Town.
- Harvey, W.H. (1894). Flora Capensis, Vol. 2, p. 327.
- ASPCA Animal Poison Control — Jade Plant. aspca.org