A citrus tree for the north! This hybrid between Poncirus trifoliata the "Hardy Orange" and the Pummello grapefruit takes periods of subfreezing temperatures with ease. Its growth and form resembles the "Hardy Orange" with fruit that is smoothed skinned and rich orange in color. This Citrumelo came from an unheated greenhouse in Newport, RI. The fruit is sour,similar to grapefruit early in the season. It has a strong root system, which is highly resistant to root diseases. We use it as an understock in grafting.