It sounds like you are doing everything properly, however, a soft, damp stem is an indication of root rot, which is typically caused by too much water in the soil. Does the pot that the plant is in have a drainage hole in the bottom? If not, water could be staying in the soil for too long.
In the winter, jade plants should be watered less often than in the summer. If you are watering approximately once a week, try extending that to once every two weeks or so.
Another factor is temperature. How cold does it get by that window? Jade plants don’t like to go below 50°F at night and colder temps from drafty windows can damage some varieties.
Unfortunately, once a jade plant has root rot, it’s hard to get it to recover. Let it sit for a while without watering and see if anything changes. If the rot spreads, you could try cutting the stem above the rot and replanting the healthy part again. If you do, let the cut part sit in the air for a few days to form a protective “skin” over the wound, then plant it in dry soil.
If the fallen leaves are healthy, you can start new plants with them by placing them on top of soil, too.
It sounds like you are doing everything properly, however, a soft, damp stem is an indication of root rot, which is typically caused by too much water in the soil. Does the pot that the plant is in have a drainage hole in the bottom? If not, water could be staying in the soil for too long.
In the winter, jade plants should be watered less often than in the summer. If you are watering approximately once a week, try extending that to once every two weeks or so.
Another factor is temperature. How cold does it get by that window? Jade plants don’t like to go below 50°F at night and colder temps from drafty windows can damage some varieties.
Unfortunately, once a jade plant has root rot, it’s hard to get it to recover. Let it sit for a while without watering and see if anything changes. If the rot spreads, you could try cutting the stem above the rot and replanting the healthy part again. If you do, let the cut part sit in the air for a few days to form a protective “skin” over the wound, then plant it in dry soil.
If the fallen leaves are healthy, you can start new plants with them by placing them on top of soil, too.