On Mon, 12 Sep 2016 11:07:54 +0100, Jim S wrote:

Why do some busy lizzies suddenly die at this time of year and others
nearby don't?

Hello,

I live in Albuquerque, New Mexico, USA. Not sure this relates to your
situation or not. In the Southwest we have to manage micro-climates. This
spot is good for our plant, and this spot two feet away is too hot, too
little sun, too dry, etc. Maybe this is what is happening?