This is a mutation of Green Doctors which is a sport of Dr. Carolyn which is a sport of Galina’s. Complicated, yes?
From Fedco Seeds:
“There are two strains of Doctors…Named in honor of the two doctors, Amy Goldman and Carolyn Male, who have written influential books on tomato varieties. Goldman discovered Green Doctors as a cherry sport of Dr. Carolyn in her 2002 garden and turned us on to it in her book The Heirloom Tomato.”
'Green Doctors Frosted' is a mutation of Green Doctors. It was discovered independently by Jeff Casey of Airdrie, Alberta, Canada and by Neil Lockhart of Oblong, Ilinois.