Sorry, here's the picture of my two very first greengage plum.

It looks like my Green Gage fruit. My tree is 8y old, and this looks like the first year I will have more than a few, if I can keep the plum curculios from destroying the remaining half of the crop! Not certain about the pollination question, but if their flowers are blooming at the same time then they will probably pollinate each other. Your trees are still young, I think you just need to keep them healthy and keep the pests and diseases away

I know others have said euro plums can take a long time to fruit...like 10 years in some cases...

Hi! I have an Italian Plum and it has taken seven years to finally have an excellent crop and that will be this summer. I am so looking forward to it. Last year I only got 24 plums. The tree has just gone through 'June Drop' and it is still loaded with a lot of plums; too many to count :) European Plums seem to take time to set fruit. I have a total of five European plums on purpose. Cross pollination always helps. Even though the Italian plum is 'self pollinating', extra pollen never seems to hurt. Mrs. G PS my 'Bavay' is too young to set fruit, but I really look forward to that delicious green plum.