Hey citradia,
I'm a fan of grapefruits and I’m definitively hoping to grow them in my place but, as you can imagine, I’m not completely sure that I’m going to get acceptable quality fruits (i have a well pronounced "sweet tooth" and while i love the bitter-acid complexity of grapefruits, the have to be sweet for me to be an enjoyable eating experience).
However, i was hoping to do what you are doing, that is, growing them for more than a year on the plant to have them ripen over the course of two consecutive summers.
I was wondering, how they turned out? How much cold did you plant take? I'm going to use bitter orange (or FD) as rootstock and Duncan/Enzo/Bloomsweet as scion. Can you help me with your tecniques and your results?
Regarding Satsumas. I have just a small plant that i have been growing for last 3 years. I'm my place the ripen fine at the end of October- November (I'm growing Miyagawa). I assume sastuma don't need very much heat overall because they come from Japan which is itself pretty oceanic and while there isn't very cold there in citrus growing place, i'm assuming there isn't very much heath either.