Crassula is a genus of roughly 200 species of leaf-succulent perennials in the family Crassulaceae, which takes its own name from this genus. Its centre of diversity is southern Africa, with secondary radiations into Madagascar and Australia. The World Checklist of Vascular Plants maintained by the Royal Botanic Gardens, Kew recognises the genus Crassula L., described by Linnaeus in 1753. One species, Crassula ovata (the jade plant, money plant, or money tree), is probably the single most widely cultivated succulent in the world. Beyond that flagship the genus ranges from tree-form shrubs to tiny packed columns and trailing mats, with a photosynthetic trick built into the family name. This guide covers what you need to recognise, grow, propagate, and troubleshoot them, with links to the species and cultivar pages that drill in further.
I'm Dr. Elena Martín, a Certified Advanced Cactus & Succulent Horticulturist and former curator of the succulent collection at the Jardín Botánico de Córdoba. Most of what follows comes from what I've seen work and fail across Mediterranean and temperate cultivation over the last decade, with particular attention to the questions readers of this site actually ask.
Is a Crassula a Succulent? And Is It the Same as a Jade Plant?
Two questions account for more traffic to this site than anything else in the genus, so it is worth answering them crisply up front.
Yes, every Crassula is a succulent. "Succulent" is a functional description of any plant that stores water in fleshy tissue, and every member of the genus does. Most store in the leaves; a few store in stems or thickened caudices as well.
A "jade plant" is one particular Crassula: Crassula ovata. The names are not synonyms for the whole genus. Crassula ovata is the species you see in nearly every florist, supermarket, and office lobby: thick glossy oval leaves, stout brown trunk, tree-like habit with age. The older names Crassula portulacea and Crassula argentea refer to the same plant and are now treated as synonyms under Kew's current taxonomy. So: all jade plants are Crassulas, but most Crassulas are not jade plants. If someone hands you a rosette of tiny overlapping triangular leaves and calls it a "jade," they either mean it loosely or they have something else in the genus such as Crassula perforata or Crassula 'Buddha's Temple'.
Taxonomy, Natural Range, and the Origin of "CAM"
Linnaeus erected Crassula in Species Plantarum (1753), and the family name Crassulaceae was built around it. The genus is centred in southern Africa, particularly the Cape Floristic Region and the Karoo, with species occupying everything from fynbos seeps to coastal cliff faces to full semi-desert. A smaller set of species occurs in Madagascar, East Africa, and Australia (C. helmsii is the familiar Australian-European aquatic representative, and is invasive in the UK). A handful of species reach into Europe as diminutive annuals.
The family gave its name to one of the most important physiological adaptations in plants: Crassulacean Acid Metabolism (CAM). In a CAM plant, stomata stay closed during the heat of the day to suppress water loss, and open at night to take in CO2. The CO2 is fixed into a four-carbon organic acid (malate) and stored in the vacuole overnight. By day, the acid is decarboxylated behind closed stomata and the released CO2 is fed through the normal Calvin cycle. The net effect is that photosynthesis happens using water economies an order of magnitude better than in a typical C3 plant. Echeveria, Sedum, Kalanchoe, Sempervivum and most other succulents also do CAM; Crassulaceae just happens to be where physiologists first nailed the mechanism down, and so the family's name stuck to the pathway.
For you as a grower, CAM has two practical consequences. First, these plants do almost all their gas exchange at night, which means ventilation and temperature drop after dark matter more than many indoor keepers realise. Second, they are efficient with water not because they dislike it but because they can keep functioning without it. Given generous drainage they accept more water than their reputation suggests.
Identification and Morphology
Crassula is diagnosable on two features that together exclude almost every lookalike genus:
- Opposite decussate leaves. Leaves arise in opposite pairs, and each successive pair is rotated 90° from the pair below it. Looking straight down at a shoot tip you see four vertical ranks. This arrangement is responsible for the stacked-column look of species like C. perforata, C. 'Buddha's Temple', and C. rupestris, as well as the orderly pairs on a jade plant's young branches. Echeveria and Sempervivum do not do this; their leaves spiral in a rosette.
- Five-petalled, star-shaped (stellate) flowers in corymbose cymes. Individual flowers are small, usually 4–8 mm across, white, cream, pink or occasionally red, and carried in flat-topped or rounded clusters on short lateral shoots. Crassula ovata in full bloom covers itself in what looks like pink-white starry foam; C. perforata produces tiny cream-coloured stars in tight clusters tucked into the leaf stacks.
Habit within the genus runs across an unusually wide range. At the large end, C. ovata and C. arborescens form woody shrubs to 2 m or more in decades-old specimens. At the small end, C. ernestii, C. socialis and the "fairy crassula" group form ground-hugging mats of stems only a few centimetres tall. Between those extremes sit the stacked columnar species (C. perforata, C. rupestris), the upright rosettes (C. falcata, C. capitella), and the densely packed cylindrical forms (C. 'Buddha's Temple', C. pyramidalis). If you cannot place a plant at first, start from the leaf arrangement, confirm decussate, and then use the later Notable Species section.
Cultivation
Crassula ovata is among the most forgiving succulents in cultivation, and the baseline settings below suit it and most of the common hobby species. The miniature southern-African species (for example C. socialis, C. tenelli, C. pyramidalis) need a tighter version of the same regime: faster substrate, brighter light, smaller pots.
Light
Bright light for at least 5–6 hours a day. A south- or west-facing window suits C. ovata indoors; east-facing will keep it alive but stretched. Most jade plants sold as houseplants are chronically under-lit. You will know yours is happy when the leaf margins develop a red or ruby blush in strong light; this is a protective anthocyanin response, not damage. A dull all-green jade plant that has never blushed has never been given enough light.
Miniature and column-forming species (C. 'Buddha's Temple', C. perforata, C. rupestris) need still more. In a windowsill setting, supplementary LED lighting is the usual fix for winters in temperate latitudes.
Outdoors, all common species tolerate full sun provided the transition is gradual. Move a greenhouse or windowsill plant directly into unfiltered midsummer sun and it will scorch in a day. Acclimate over two weeks through 30% shade cloth.
Substrate
Free-draining mineral mix. My standard recipe is 50% pumice or perlite, 30% coarse grit (3–5 mm), and 20% peat-free loam-based compost such as John Innes No. 2. Crassula ovata and its hybrids tolerate heavier mixes than most, but the rarer miniatures rot within weeks in anything too organic. Off-the-shelf "cactus compost" from general garden centres is usually too peaty and benefits from cutting with an equal volume of pumice.
pH preference is slightly acidic to neutral, roughly 6.0–7.0. Hard tap water over years nudges substrate pH upward and can lock out iron and manganese. Water with rainwater or RO water where you can.
Water
The most common killer of potted Crassulas is chronic overwatering in cold, low-light winter conditions. The rule that works better than a schedule: water when the top 3–4 cm of substrate reads dry on a moisture meter, then water thoroughly until excess runs through the drainage holes. Empty any water standing in the saucer within 30 minutes.
In practice that means summer outdoor C. ovata gets a soak roughly once a week; a cool winter windowsill specimen may go 4–6 weeks between waterings. Leaves that become soft, wrinkled, and slightly translucent are telling you they are running dry; leaves that become soft, yellow-translucent, and actually squishy are telling you the roots have drowned and rotted. The two look similar at a glance. If in doubt, unpot the plant and look at the roots.
Crassulas are not winter growers in the strict horticultural sense. The majority of southern-African species have a main growth flush in late spring and early autumn, slow through the hottest weeks of summer, and largely stop in winter if kept cool. Water accordingly: heavy in growth, sparing in dormancy.
Temperature
C. ovata and most commonly cultivated species tolerate 5°C–35°C. Sustained temperatures below 4°C produce leaf drop and, if the tissue is wet, fast rot. None of the common species is reliably frost hardy. A brief touch of −1°C on dry tissue is sometimes survivable; anything worse, or any frost while the plant is wet, will kill leaves and often branches outright. If you have been told a crassula is "frost resistant," the claim is almost always overstated. Protect below 5°C.
Humidity
Ambient 30%–60% is fine. Higher humidity combined with still air invites powdery mildew and soft rot, both common in Crassula collections kept in unventilated greenhouses. These plants never need misting; water pooling in the rosette crown of a compact species like C. 'Buddha's Temple' is a direct invitation to crown rot.
Propagation
Almost every Crassula you will keep can be propagated four ways, and the first two are reliable enough that stock is effectively unlimited once you have a healthy parent plant.
Leaf propagation
Detach a mature, undamaged leaf with a clean sideways twist so you take the whole basal connection, not a torn stub. Let the cut callus over for 3–7 days in dry shade. Lay the leaf on lightly damp gritty substrate with the base just touching the surface. Keep bright but out of direct sun, at 20°C–25°C. New roots and a miniature plantlet appear in 2–4 weeks. Leaf propagation works extremely well for C. ovata, C. arborescens, C. capitella, C. perforata, and most of the common hobby species. A few miniatures (C. socialis, C. tenelli) are faster from stem pieces because their leaves are too small to generate meaningful callus tissue.
Stem cutting
Cut a 5–10 cm section with sterile secateurs, strip the lower leaves, callus for 5–10 days, then insert 2 cm into gritty substrate. Stem cuttings root reliably for tree-form species and fast for column-formers. Cuttings can also be rooted in water; C. ovata tolerates this surprisingly well and produces fine water roots in 2–3 weeks, though you will need to harden them off slowly before planting into mineral substrate.
For the tiny stacked-stem species, there is a useful and slightly eccentric trick: take a short cutting of C. rupestris or C. perforata, shake it vigorously in a tray of dry gritty mix so that loose leaves scatter and the stem lies flat, then mist once a week. Within a month the stem will have rooted, most of the scattered leaves will have started new plantlets, and you will have a full pot of clones from one cutting.
Division and offsets
Mature clumps of mat-forming species (C. socialis, C. muscosa, C. pangolin) can be split by hand or sharp knife in spring. Let the cut surfaces dry for a day, then repot into gritty mix.
Seed
Possible but slow, and only worth it for rare species where vegetative material is scarce. Most Crassula flowers are self-compatible and will set seed on an isolated plant, but germination is erratic and seedlings take 2–4 years to reach interesting size. Sow on the surface of a damp gritty mix, cover with glass, and keep at 20°C. Prick out as soon as seedlings are handleable.
Pruning, Shaping, and Bonsai
Crassula ovata is arguably the single most-used succulent in bonsai, and for good reason: it responds to pruning with vigorous back-budding, its natural growth pattern already mimics a deciduous tree in miniature, and its trunk thickens surprisingly fast under regular cuts. If you want a convincing tree-form jade in five years, start with a young whip and shorten every new shoot back to two or three leaf pairs through each growing season. The wounds heal cleanly if cuts are made just above a leaf pair with clean bypass secateurs.
For a normal houseplant jade, pruning is mostly cosmetic. Remove branches that cross, branches growing into the centre of the canopy, and any leggy shoots produced during a dim winter. Prune in spring as the plant resumes growth; avoid pruning into cold, dormant tissue.
Across the rest of the genus, pruning is rarely necessary. Trailing species may be shortened to control shape, and the cut-off pieces become new plants under the leaf-propagation procedure above.
Common Problems
| Symptom | Likely cause | Fix |
|---|---|---|
| Lower leaves yellow, soft, and translucent | Overwatering, often with cold roots | Stop watering; unpot and inspect for root rot; repot into dry gritty mix |
| Lower leaves wrinkled but firm; whole plant limp | Under-watered | Water thoroughly; leaves rehydrate within 24–48 hours |
| Lower leaves drop spontaneously | Sudden cold, draught, or dramatic watering change | Stabilise conditions; leaf drop from a recently-moved plant is usually temporary |
| White cottony tufts in leaf axils and on roots | Mealybug | Spot-treat with cotton swab dipped in 70% isopropyl alcohol; systemic treatment if widespread |
| Grey-white powdery film on leaves | Powdery mildew (Erysiphe) | Improve ventilation, reduce humidity, treat with sulphur or potassium bicarbonate |
| Soft black patches at stem base spreading upward | Root and crown rot (usually Pythium or Fusarium) | Cut well above the rot, discard the base, re-root the top as a cutting |
| Elongated stem, widely spaced pale leaves | Etiolation from under-lighting | Increase light; behead and re-root to reset compact form |
| Leaves turning bright red across whole plant | Stress colour from strong light, cold, or drought | Usually cosmetic; reassess only if accompanied by shrivelling |
| Leaves turning brown and crisp at tips | Sun scorch, hot wind, or accumulated salts | Move out of direct hard sun; flush the substrate with rainwater |
| Plant flowering then declining | Not monocarpic; a spent inflorescence simply needs removal | Cut flower stalk at base once bloom finishes |
Two questions on safety come up constantly, and deserve direct answers. Crassula ovata is listed by the ASPCA as toxic to cats, dogs, and horses, with symptoms including vomiting, incoordination, and depression. The specific toxin has never been fully identified but the effect is well-documented. Crassulas are not known to be seriously toxic to healthy adult humans at the doses anyone would accidentally ingest, but they are not food plants and a child chewing leaves may vomit. If you keep pets, place jade plants out of reach or choose a different genus.
Notable Species and Cultivars
The genus is far too large to cover species-by-species here. Below are the ones most worth knowing, grouped by growth habit, with links to their dedicated pages.
Tree-form and shrubby
- Crassula ovata — the jade plant / money tree; the flagship species, forgiving and long-lived.
- Crassula ovata 'Gollum' — tubular "finger-jade" leaves; a fixed mutation of C. ovata.
- Crassula arborescens — silver dollar jade; blue-grey rounded leaves with red margins.
- Crassula portulacea and Crassula argentea — older names now treated as synonyms of C. ovata.
- Crassula ovata (bonsai training) — dedicated page on shaping tree-form jades.
Stacked-column and "string" forms
- Crassula perforata — string of buttons; triangular leaves threaded on upright stems.
- Crassula rupestris — buttons on a string; similar to perforata but with fused leaf pairs.
- Crassula 'Buddha's Temple' — tightly stacked columnar hybrid of C. perfoliata × C. pyramidalis.
- Crassula capitella — campfire crassula; turns bright red in full sun.
- Crassula capitella 'Campfire' — selected red-leaved cultivar.
Upright rosettes and sculptural species
- Crassula falcata — propeller plant; grey sickle-shaped leaves in a single plane.
- Crassula 'Morgan's Beauty' — compact hybrid with dense pink flowerheads.
- Crassula 'Moonglow' — columnar silver-leaved hybrid.
- Crassula 'Platyphylla' — flat-leaved form used in mixed-succulent plantings.
Miniatures and mat-formers
- Crassula muscosa — watch-chain crassula; tiny scale-like leaves on wiry stems.
- Crassula socialis — dense cushion-forming miniature.
- Crassula tenelli — small mat-former, fast from cuttings.
- Crassula pangolin — overlapping-scale miniature.
- Crassula cephalophora — small rosette species, compact in strong light.
- Fuzzy Crassula — hairy-leaved miniatures including C. mesembryanthemoides.
- Fairy Crassula — common-name grouping of the smallest mat species.
Other species worth knowing
- Crassula alba — upright summer-flowering species with red inflorescences.
- Crassula alata — small winter-growing annual from Mediterranean climates.
- Crassula alpestris — high-altitude compact species.
- Crassula umbella — "wine cups"; fused perfoliate leaves holding the flower stalk.
- Crassula sarmentosa — trailing variegated species for hanging pots.
- Crassula conjuncta — now usually synonymised with C. perfoliata var. minor.
- Crassula obvallata — clump-forming rosette species.
- Crassula spiralis — spirally-stacked leaves on short stems.
- Crassula imperialis — obscure miniature species.
- Crassula marginalis — trailing red-margined species.
- Crassula obliqua — older name sometimes applied to forms of C. ovata.
- Crassula calico and Crassula 'Dorothy' — variegated hybrids.
- White Crassula — common-name grouping for C. alba and white-flowered hybrids.
- Variegated Crassula — notes on variegation stability.
- Crassula species — unidentified and orphan records.
Closing Notes
If you are new to the genus, buy a Crassula ovata. A healthy specimen arrives with a firm trunk, plump glossy leaves, and no black patches at the soil line. Pot it into gritty mix, put it on your brightest windowsill, water it when it dries out, and keep it out of frost. You will have the same plant in twenty years, and it will be substantially larger. Everything else you learn on it transfers to the rest of the genus, with adjustments toward faster drainage and brighter light as you move into the miniatures.
For specific cultivation, propagation timing, and pest problems, follow the species links above. For the physiology behind the family name, and why these plants behave so differently at night than during the day, the short answer is CAM; the long answer is what lets every succulent on your shelf survive conditions that would flatten most of the plant kingdom.
If you are arriving at succulents for the first time, the beginner's guide to succulents covers the cross-genus basics — light, water, substrate, and the common early mistakes — and is the right starting point before any single-genus deep dive.