Thanks for those really evocative pictures!
It is a gorgeous place: we went in October, and it was equally glorious then - I expect it will be at any time of year. It's run, incidentally, by our forum member "Alevin".
The Italian branch of the MGS is arranging a tour to Naples and Ischia this September, which will include La Mortella; they say they'd be happy for members of other MGS branches to join them.