(Photograph = Crassula columnaris, Martin Heigen)
Introduction
Crassula is one of those “everyone knows it” succulent groups, even if the name comes later. Most people meet it through jade plant—Crassula ovata—a forgiving, woody succulent that can live for decades, take a good pruning, and bloom in cool seasons with starry white to pale-pink flowers. But Crassula is much wider than jade. The genus runs from stacked, architectural miniatures to rangy shrubs, from silver-blue paddles to tight, watch-chain stems. What unites them is a simple playbook for dry places: water-storing leaves, night-time gas exchange when it’s cooler, and a skin that throttles loss on hot, windy days. It’s tough, adaptable geometry that happens to look elegant on a windowsill or in a crevice garden.
The Details
Most Crassula species are southern African, with outliers that wander north and a few that have gone global in cultivation. Leaves sit opposite on the stem—often thick, sometimes edged in red, occasionally stacked into tidy towers. The variety is half the fun. C. ovata and C. arborescens give you the classic, woody “tree” habit; C. perforata (“string of buttons”) climbs by stacking diamond-shaped leaves along a twining stem; C. muscosa knits tight mats of tiny, overlapping leaves that read as living braids; C. capitella (‘Campfire’) flushes copper and scarlet in strong light. All of them follow a similar rhythm: store water when it’s available, slow their metabolism when it’s not, and thicken stems and leaves to ride out the gap between rains.
Bloom is a bonus rather than the point. Many species flower when nights turn cool and days stay bright; in the jade group that often means mid-winter sprays of small, five-pointed stars. Indoors, blooms come most reliably when plants have a real drop in night temperatures, plenty of light, and soil kept on the dry side once growth slows. Outdoors in mild climates, the show can be generous, with bees working the flowers on sunny winter days.
Culture is simple if you follow the script. Give bright light to full sun, a fast-draining mineral mix, and watering in clear pulses: drench thoroughly, then wait until the pot is bone-dry before watering again. In the ground, plant on a slope, in raised beds, or in crevices where crowns sit high and dry. Most losses trace to heavy, water-holding soils, cramped pots with poor drain holes, or frequent “sips” that keep roots damp and cold. Indoors, a south- or west-facing window usually suffices; rotate plants every couple of weeks to keep the form even, and resist the urge to water on a schedule. Leaves that wrinkle softly signal thirst; leaves that feel squishy signal too much water. In cold regions, protect from hard freezes; brief, dry dips near the mid-20s °F may pass without harm for mature jade, but wet and cold together is the real risk.
Crassula lends itself to shaping. Pinch or prune to build a branching framework, then let new shoots harden before the next cut—classic bonsai logic on a forgiving plant. Propagation is equally easy. Stem cuttings root quickly if you let the cut end callus for a day or two, then set it in a gritty mix and hold off on water until you see new growth. Many species also root from single leaves laid on the surface and left alone.
Expect a few common pests. Mealybugs love the sheltered joints where leaves meet stems. A cotton swab dipped in isopropyl alcohol and a steady hand will clear light infestations; better air movement and brighter light help prevent them from returning. Scale and spider mites appear now and then under warm, stale conditions—again, airflow and a leaner watering routine are your friends.
A note on look-alikes: Portulacaria afra (elephant bush) is often mistaken for jade. It carries smaller, thinner leaves and a looser, twiggy build, and it stays greener in strong sun where jade may blush at the edges. Both make sturdy, water-wise shrubs in frost-free gardens, but the feel in hand is different—jade leaves are thicker, with a soft gloss; elephant bush leaves are thinner and slightly translucent. If you garden with pets, keep in mind that jade is not for nibbling; site it out of reach and sweep up prunings.
In short, Crassula is more than a single houseplant. It’s a broad, resilient toolbox of forms—from tabletop miniatures to sculptural shrubs—that rewards bright light, patience, and a light hand with water. Grow it the way it evolved: sun, space, and sharp drainage. The rest—clean lines, winter bloom, and those satisfying, weighty leaves—takes care of itself.
Additional Reading: Crassulaceae
