Ripple jade, Crassula arborescens subspecies undulatifolia, is the most sculptural of the jade plants and the slowest growing. Its leaves are blue-grey, thick, and distinctly wavy along the edge, and in strong light those edges colour to deep maroon. It makes a compact shrub of about a metre in a pot over many years, holds its shape without pruning, and asks for almost nothing except drainage. The one thing that reliably kills it in Australia is a humid summer combined with a mix that stays damp, and that is entirely preventable.
Quick facts
| Attribute | Detail |
|---|---|
| Botanical name | Crassula arborescens subsp. undulatifolia |
| Common names | Ripple jade, curly jade, silver dollar jade |
| Mature size | 1m x 80cm in a pot, larger in the ground over decades |
| Growth rate | Slow, roughly 5cm to 10cm a year |
| Light | Bright light, including several hours of direct morning sun |
| Watering | Every 10 to 14 days in summer, monthly in winter |
| Frost tolerance | Damaged by frost, keep above about 5C |
| Flowering | Small white to pale pink star flowers, occasional, in winter |
| Propagation | Leaf or stem cuttings, callused before planting |
Choosing the right position
Ripple jade wants more light than most people give it. Indoors, that means directly beside a north-facing or east-facing window, not two metres into the room. In the southern hemisphere a north-facing window is the brightest aspect in the house, and a plant a short distance back from one will stretch and lose the wavy leaf shape that makes it worth growing. Insufficient light is the most common reason an indoor ripple jade looks nothing like the photograph.
Outdoors in the subtropics, give it morning sun and shelter from heavy summer rain, such as under an eave or a covered patio. In drier inland and southern districts it takes full sun happily. The maroon leaf edges only develop under bright light and mild stress, so a plant grown soft in shade stays plain grey-green.
It suits a pot better than a garden bed on the east coast, because a pot lets you control both drainage and rainfall. In a garden it needs a raised, free-draining position and it will not survive a frost pocket. It combines well with other blue-grey succulents such as blue chalk sticks, covered in our guide to growing blue chalksticks.
How to plant
Use a gritty, free-draining mix. Three parts premium potting mix to two parts coarse washed sand or 2 to 5 millimetre gravel plus one part perlite or scoria works well, and a bagged cacti and succulent mix with extra grit added is a good shortcut. The mix should crumble in the hand rather than clump.
Choose a pot only two to four centimetres wider than the current one and make sure it has generous drainage holes. Terracotta suits this plant better than plastic or glazed ceramic because it breathes and dries faster. Plant with the base of the stem at the surface, never buried, and top-dress with 20 millimetres of gravel rather than bark mulch, which traps moisture against the stem.
Wait about a week after potting before the first watering so any damaged roots can seal. Repot every three to four years; ripple jade is slow and resents disturbance, and it flowers more readily when slightly pot-bound.
Ongoing care
Watering
Water thoroughly, then let the mix dry out completely before watering again. In practice that means roughly every ten to fourteen days from October to March, and about once a month from April to September. Reduce further during a wet, humid spell, since the plant absorbs moisture from the air and the mix dries slowly. Water the mix rather than the foliage, and water in the morning so any splashes dry before nightfall.
Feeding
Very little is needed. One half-strength application of a controlled-release fertiliser in early spring covers the whole year. Overfeeding produces soft, elongated growth that flops and loses the compact branching form, and it makes the plant far more vulnerable to rot.
Pruning
Ripple jade holds its shape without pruning, which is part of its appeal. Prune in early spring only to remove damaged growth, to open the canopy so air moves through it in humid weather, or to balance a lopsided plant. Cut just above a leaf pair; it branches from that point. Keep every cutting, because they strike readily.
Propagation from leaf and stem
Stem cuttings are the fastest method. Take a 10 to 15 centimetre piece, strip the lower leaves, and leave it in a dry, shaded spot for three to seven days until the cut face has sealed over. Push it into barely moist gritty mix and do not water for a fortnight. Roots usually form within four to six weeks.
Leaf propagation is slower but works. Twist a whole leaf off cleanly at the stem so none of the base is left behind, callus it the same way, then lay it on top of dry mix and mist lightly once a week. A small rosette and roots appear at the leaf base within four to eight weeks, and the parent leaf shrivels away as the new plant takes over.
Common problems and fixes
Soft, yellowing, translucent leaves that drop at a touch mean too much water, and in a Brisbane summer that is the default diagnosis. Stop watering, move the plant somewhere airy with better light, and check that the pot drains freely. If the base of the stem has gone soft and brown the plant will not recover, so take cuttings from the firm upper growth immediately and start again.
Black or brown spots on leaves after a humid spell are fungal and follow still air. Thin the canopy, stop any overhead watering and improve airflow. Stretched stems with wide gaps between leaves and flat, unwaved leaves mean insufficient light; cut back hard in spring and move the plant into stronger light gradually over two weeks so it does not scorch.
White cottony clusters in leaf joints are mealybug, the most common pest on jades. Dab each cluster with a cotton bud dipped in methylated spirits and repeat weekly until clear. Wrinkled leaves that remain firm mean the plant is genuinely dry, which is uncommon and corrected with a single deep watering. Leaf edges scorched white after a move into strong sun are sunburn, and the damage is permanent on those leaves though the plant recovers.
Frequently asked questions
How often should I water a ripple jade?
Every ten to fourteen days in summer and roughly monthly in winter, and only once the mix has dried right through. In humid coastal weather stretch the interval further, since the mix stays damp much longer than it looks.
Is ripple jade the same as a jade plant?
They are close relatives but different plants. The common jade is Crassula ovata, with flat oval green leaves. Ripple jade is Crassula arborescens subspecies undulatifolia, with thicker blue-grey leaves that are distinctly wavy at the edge and often rimmed in maroon.
Can ripple jade grow indoors in Australia?
Yes, provided it sits directly beside a north-facing or east-facing window. Anywhere dimmer and it stretches, loses its leaf shape and becomes prone to rot because the mix dries too slowly.
Will ripple jade survive frost?
No. It is damaged by frost and is best kept above about 5 degrees. In frost-prone districts grow it in a pot that can be moved under cover for winter.
How do I propagate ripple jade?
Take a stem cutting 10 to 15 centimetres long, let the cut face callus for three to seven days, then plant it into gritty mix and withhold water for two weeks. Whole leaves callused the same way and laid on dry mix will also strike, taking four to eight weeks.
Why is my ripple jade dropping leaves?
Soft, translucent leaves dropping means overwatering. Firm, wrinkled leaves dropping means it has been dry too long. In Australian coastal gardens the first is far more common than the second.
Ready to plant?
Get the mix gritty and the light bright and it will outlive most things in the house. Ripple jade sits alongside the rest of our succulents range and the wider succulents and cacti collection, and our guides to succulents in Australia and low-maintenance cacti cover the plants that suit the same conditions.
