Unlike peaches and apricots some plum need to be cross pollinated.

Now, I want to buy an advanced (i.e.≥ 2 years old) Coe’s Golden Drop:

https://www.woodbridgefruittrees.com.au/138-large_default/coe-s-golden-drop.jpg

Woodbridge:

Quote:

Coe's Golden Drop This famous old English plum has a clear yellow skin and gorgeous yellow flesh with a sweet melting flavour. Amazing eaten (juicy!), and good for stewing and jams. Pollinated by Damson, Angelina, Greengage. Ripens late February

Another site called it “the Cox Orange Pippin” of the plum world. A delicious plum!

It needs to be pollinated, Woodbridge again:

Quote:

Coe's Golden Drop. Reference: This famous old English plum has a clear yellow ... Pollinated by Damson, Angelina, Greengage. Ripens late February. More details.

Peter Cundall:

Quote:

The best flavoured of all is Golden Gage, which carries excellent crops of soft-yellow, golf-ball-sized, wonderfully flavoured, juicy fruit. This is the best pollinator for Greengage by the way, far more reliable than Coe’s Golden Drop, which often comes into bloom too late to do the job.

https://www.weeklytimesnow.com.au/country-living/gardening/peter-cundall-prunes-shaken-and-served/news-story/14cacb401a487e30be48cca63fc358e8

(I was trying to find the article where Peter goes off his nut about people saying Coe’s Golden Drop was a pollinator for Green Gage  ;D )

I sent an email to the nursery that supplies advanced trees, Monday I should know what is available and will work out an order. Could end up with three Japanese plum trees!