Question
John,
I have a Jade tree that for years has had fine spider webs at the dirt.  I assume spider mites.  I've sprayed and I repotted the plant with new dirt.  That repotting 2 years ago damaged the roots and it's had a hard time supporting itself.  Lately I see thata the spider webs are back.  Also each morning I find leaves fallen that have black squishy damage.  But when I look at the leaves on the plant they seem fine with none ready to fall.  Sounds like I have might have two pests.  Does this sound familiar?  Is the tree a goner, or should I repot?  I have been spraying for spider mites every few days and vacumming up the web but it doesn't seem to help.

Answer
Charlie,

First of all, is the plant outdoors? If not, you could be having a top heavy plant because in low light, the plant cells elongate.  In either case, I would take several cuttings from the plant and re-root them (as an insurance policy).  If there is a disease (black squishy?), then you may be able to save the plant by taking a cutting from an unaffected part of the plant.

Most all spiders are beneficial insects, so unless you know for sure that you have spider mites (not true spiders), then I wouldn't take any extra precautions to control the spider population.  (Placing the plant outdoors will usually take care of the spider mites.)

I have had no experience with jade trees, so my knowledge is limited, but if the leaves do not appear damaged on the tree, then I would not assume that they are diseased.  

Sorry, I couldn't be of more help.

I would repot and check the root system for any foul odor.  Additonally, take several (four or five) cuttings and from them you should be able to root two easily. (These root easily in sand or peat-based potting medium).