Crassula ovata (Mill.) Druce

Jade plant · Money plant · Friendship tree

Family: Crassulaceae
Native to: South-eastern Mozambique to the south-eastern Cape
Habit: Succulent shrub
Also known as: Crassula argentea Thunb.

Where it comes from

Kew gives the native range as south-eastern Mozambique to the south-eastern Cape — the Cape Provinces, KwaZulu-Natal and Mozambique.¹ That last one is the bit that gets dropped: NC State says South Africa and stops there.² It has naturalised in California, the Canaries, Madeira, Portugal, Spain and St Helena.¹

The red margins on a plant in good light are not stress. SANBI’s description of the wild plant gives leaves of 3-9 cm “with reddish margins” as a characteristic,³ and Wisconsin notes the colour simply does not develop in a plant kept too dim.⁴ I could not find the pigment chemistry documented for this species specifically, so the page says the colour is light-driven and stops there.

Naming and description

Watch the author string, because there are two Crassula ovata. The jade plant is (Mill.) Druce. There is also a C. ovata E.Mey. ex Harv., which Kew does not accept and treats as a synonym of Crassula sarmentosa.⁵⁶

Crassula argentea is the old name still in wide circulation, and it is a genuine synonym rather than an error — the ASPCA’s own toxicity page is still filed under it.⁷⁸

Fun facts

CAM is not about when you water, and the advice built on that is nonsense. This family gave Crassulacean Acid Metabolism its name: the stomata stay shut through the day and open at night, carbon dioxide is fixed into organic acids in the dark, then released and photosynthesised the next day behind closed pores.³⁹ That is a leaf gas-exchange schedule, not a root-uptake schedule, and nothing in the literature connects it to the time of day you fill the watering can. What it does mean is worth knowing: the plant runs at very high water-use efficiency and is built to sit dry, and its daily carbon gain is modest by design — one review calls CAM “a strategy for variable, flexible and plastic niche occupation rather than lush productivity”.⁹ Which is why it grows slowly and wants almost no feeding.
And it does not switch to normal photosynthesis when you water it. The facultative-CAM story gets attached to jade plants constantly. I went looking for it: a 2019 review tabulating more than fifty facultative CAM species across twenty-seven genera lists Crassula sieberiana, not C. ovata,¹⁰ and a 2014 paper naming the five best-established terrestrial facultative species does not include it either.¹¹ Treat it as constitutive CAM. The grain of truth is that the amount of carbon coming through the CAM pathway varies enormously — anywhere from under one per cent to all of it¹⁰ — which is modulation, not switching.
A gnarled trunk is not evidence of age. Wisconsin puts it well: the woody, ancient-looking stem develops “even in young specimens”, which is why old-jade folklore is so persistent.⁴ The famous longevity is anecdote; nothing at extension or botanic-garden level documents a lifespan.
A jade beside a lamp will never flower. Blooming is triggered by long nights — Wisconsin specifies nights around 55 °F (13 °C) and no supplementary light at all.⁴ So the usual explanation, that the plant is not mature enough, is usually wrong; the evening reading lamp is the reason.
Do not reach for insecticidal soap. It is the standard houseplant reflex for mealybugs, and Clemson says explicitly to avoid it on jade plants, with Wisconsin flagging phytotoxicity independently.¹²⁴ Alcohol on a cotton bud is the documented alternative.
Nobody knows what makes it toxic. The ASPCA lists it as toxic to cats, dogs and horses — and gives the toxic principle as, in its own word, “Unknown”.⁷ A pet poison service rates the effects mild and self-limiting.¹³

Care

Light: Four or more hours of direct sun a day, or a bright south-facing window — two extension services give the same figure independently. No source at this level publishes a lux number. Too little light gives deep green leaves, drooping stems and no red in the margins; the compact shape is a light effect, not a genetic one.
Water: Let the mix dry out, then water deeply. Overwatering drops the leaves and rots the stem, and it is the way most of these die. Cut back sharply in winter — that is well documented as practice, though it is horticultural practice rather than anything derived from the plant's physiology, and it is worth being honest about which.
Humidity: No requirement. Ordinary dry room air is what it is built for.
Temperature: 65-75 °F (18-24 °C) by day and 50-55 °F (10-13 °C) at night is the published optimum. The cool nights are not an indulgence — nocturnal gas exchange is when a CAM plant does its work.
Substrate: Free-draining and gritty — a cactus mix, or ordinary compost cut heavily with sharp sand or perlite. Depth matters less than drainage; these are shallow-rooted.
Fertilizer: Very little. Clemson feeds once every three or four months. A CAM plant's daily carbon gain is modest by design, so feeding it like a fast-growing foliage plant gives it nothing it can use.
Propagation: Leaf and stem cuttings, both easy. Let the cut surface callus before it touches the mix. No extension source I found gives a rooting timescale, which is worth knowing before you conclude yours is slow.
Dormancy: None documented as a physiological rest. Growth slows in winter with the light and the temperature, and the watering follows.
Common problems: Root and stem rot from overwatering — far and away the commonest cause of death, and the reason the pot matters more than the plant
Leggy stems with widely spaced deep-green leaves and no red margins mean too little light
Mealybugs and spider mites. But do not reach for insecticidal soap: Clemson warns it may damage jade plants and Wisconsin flags phytotoxicity independently. Alcohol on a cotton bud is the documented alternative
Leaf drop after a period of drought is normal and recoverable; leaf drop on a wet plant is not
A plant that never flowers is usually beside a lamp. Flowering is triggered by long nights, so a plant getting evening light indoors will not do it
Every part is toxic to cats and dogs, and unusually the toxic principle has never been identified