Shiro Plum Cross Pollination

Shiro plums are delicious. They are self pollinating but I've noticed that for 2yrs in row the production for this tree has been abysmal. I do have an italian plum tree but it's across the entire yard and not an compatible pollinator for the Shiro. I may have to pick up another variety to help it with the cross pollination and increase the yield. Most likely the Methley Plum.

For cross-pollination, trees must bloom at the same time or have overlapping bloom periods. "Redheart," "Early Golden," "Ozark Premier" and "Methley" cultivars pollinate Shiro plum trees. "Methley" is a low-chill-requirement plum tree with hardy blossoms, making it compatible with Shiro plum in mild-winter locations. "Starking Delicious" is a registered cultivar that shares the same bloom period and cultural requirements as Shiro plum, making this tree a suitable pollinator for Shiro plum. Because these plum trees are all cultivars of the Japanese plum, Prunus salicina, according to the definition of Lerner and Hirst, Shiro plum is self-fruitful. In this case "self" refers to the species, not the particular cultivar. Although a single tree may set a small crop of fruit, heavier crops result from pollination by another cultivar.

Update 6/29/17

I picked up a Satsuma to pollinate my shiro and a green gage plum to pollinate my italian. I also picked up a Lapins Cherry to pollinate my Bing.