Hi I f you still have cuttings off your dwarf jade bonsai you can start a new 'plant' let the stems rest for a day and then plant them in some good drainidge compost water the compost first then stick your cuttings in the compost within 3 weeks you should have roots and a new plant. good luck

It sounds like Portulacaria afra, which doesn't tolerate wet feet well at all. Test the plant by moving it side to side to see if it's still secure in the pot. Usually roots rot off the main stem very quickly when they're over-watered and the plant often simply falls over. If you've lost most of the rootage, you'll essentially need to treat the plant as a cutting and hope you can reroot successfully after removing rotted tissues so only sound roots remain. Al

Watering is the trick. Now we would need to know what soil it is currently planted in. Fast draining soils would need to be watered more often than peat based soils. Environment, for instance humidity and temperature would effect when to water. You kinda have got to figure this out for yourself. You already noted that you where over watering. If you start to underwater you will notice the leaves will start to shrivel. Poke your finger in the soil. It should be slightly damp to almost dry near the top before you water. Poke deep so as to make sure the bottom is not saturated while the top is not dry. I use a gritty Soil mix for my succulents. Something that drains well. In little time you should be able to figure what your tree needs. Jade is very forgiving. You overwatering is probably the worst of the evils you could inflict on this species and it looks like it will survive. Good luck and if you still have problems watering, check back and we can diagnose further. For now try to observe and create your own watering schedule.

Thank you everyone! I will take it out tonight , I'm thinking proportionally less potting mix this time. Do I need to leave the roots out for a few days before repotting? I admit I've put them straight into a fresh mix previously. And then hold off watering for 1-2 weeks? Would you still recommend removing the black leaves if I add that they feel firm and healthy (despite their unhealthy appearance!)? I've just noticed that the poorly coloured squishy ones (most of the leaves on the plant) also look more swollen than the bright green/red ones... definitely over watering / lack of soil drainage.