The trifoliata I have bears many fruit but the only thing I have found the
fruit to be good for is to use as a sachet in drawers (the chest of drawers
type). The pulp is cathartic in some people as I found accidentally and
lost a friendship. I like the flavor but scummy consistency (pectin?)
discourages most folks from eating much of it; plus they are very seedy.
I saw a use which I hadn't thought of before in China where they use the
bushes as thorny barriers to discourage people from trampling their
gardens. I wouldn't say that trifolate orange would be harmed by Zone 5
temperatures. In China where I saw many of them gets very cold but I don't
know exactly how cold.
Doc
Zone 7/8