Ouillins Golden Gage is one of the most reliable gages to grow. It is self-fertile and late-flowering and quite frost-resistant. If grown well, it is a healthy and vigorous tree with good sized fruits, ready to harvest by mid-August. It is a dual-purpose (dessert/jam) plum/greengage and a regular cropper. Suitable for the North in a sheltered position.
Read an article on plum, greengage and damson pollination, with a pollination compatibility chart.