My jade plant needs help desperately!
There is some kind of black stuff on my jade's leaves that looks like tar. Also many leaves are yellowing, and some look brown and almost burnt...what's going on? It's still trying to flower now, and my moisture meter says it's on the dry side.
Hi Nancy, without some images of the issue, I'm not sure what would be happening.
As you're in California, I'm going to assume that your plant has not experienced frost.
The black stuff you describe could be sooty mold - unsightly, but not a problem in itself. The problem is that sooty mold needs honeydew, the stuff that aphids, scale and other insects excrete. If you look closely, it might be obvious that your plant has scale, which are small bumpy shells as adults, and mobile forms of the juveniles called crawlers. As they don't move as adults, they can avoid detection because they look like the bark.
If this is the problem, start a spraying program right away. Some kind of home made spray containing some kind of oil; horticultural oil called summer oil is good, or use a few drops of plain old cooking oil like sunflower or safflower oil and a small amount of dish soap mixed in a sprayer with tepid water.
This is a good multi purpose spray that is generally safe to use - don't leave your plant in the full sun when it's wet with this, as it can sunburn the leaves.
Continue to spray on a daily basis for at least a week, and then monitor the situation.
All plants will lose some leaves - again without seeing what's going on, I can't say for certain what would be causing this with your Jade plant.
At this time of year, they will be losing some due to lower light levels and day length.
If it's not an excessive amount (say, no more than 10-15% of the total number of leaves) then don't worry about it, the plant will make more.
These plants do tend to grow a 'trunk' and a head of foliage, so this is normal.
Plants typically will start to bloom when they're under stress. You can cut the flowers off to give the plant more resources to fight off whatever is attacking it if you like.
Propagate a few of the healthy parts to create more plants to take its place if it doesn't make it.
Hope these suggestions help.