Forgot the ref...

Satsuma Japanese plums are fast growing, but not self fertile. You will need more than one Satsuma if you want them to bear fruit. Good choices for companion pollinating plum trees are, of course, another Satsuma or one of the following: “Methley,” a sweet, red plum “Shiro,” a large, sweet vibrantly yellow plum “Toka,” a red hybrid plum

Read more at Gardening Know How: Satsuma Plum Ca Learn About Japanese Plum Growing https://www.gardeningknowhow.com/edi...-plum-care.htm