Question
Can you comment on why Red Apple is dying in California.  I see that writers from San Diego wrote to Melissa Johnston, too, regarding dying plants.  We live near Los Angeles and have driven around various neighborhoods to see similar dying Red Apple.  We have over a 1/2 acre of hillside Red Apple, which started to die last summer (2015) and continues today so it's not too much water (drought stricken Calif).  The dying vines started mainly in areas not under tree shade but rather out in the open.  The leaves die first followed by the vine...they turn dry and brown becoming brittle. Our hillside is becoming barren, watering doesn't help, is it a fungus?  Could it be a vector spraying?  Could it be something in the water or rain (when we get it)?  Help!

Answer
Sharon:

This succulent ground cover is common in dry/arid areas.  It is also referred to as "ice plant" or baby sun rose and is also grown as an erosion management tool especially on sloped areas. It may live only 2-3 years and may need to be replaced as plants die off naturally.  It may suffer if night time temps drop below 50 degrees.

From a plant disease standpoint, this plant can develope root and lower stem rot that is caused by a fungus called Phytophthora.  This fungus is very often associated with wet/poorly drained soils.  So, if the soil remains wet for extended periods or does not drain well, this fungus can kill plants. This is the only major infectious problem of this plant that I am aware of.  There may be other issues, perhaps environmental in origin that may account for widespread losses of this plant.  

Symptomatic plants would need to be examined in a lab environment to determine the exact cause. You can contact your local County Extension office to arrange for this exam.  There is usually an office in each county and is housed in the courthouse with other county offices. The lab is usually affiliated with a land grant university such as UCLA or UC Riverside.

Regards
Steve