The asian plum population is on the way out very soon around PDX. So this has been a spring that I have seen much less activity in the way of pollinators. The little tiny (ant with wings) critters or wasps are not around so far. Maybe the cold winter hampered the little guys?
Sweet cherries are starting and as I was out looking for pollen to hand pollinate my 'early burlat' cherry I decided to take a pollen picture of a flowering cherry species so that you can see something about what might not be happening very much now.
<----- so click the link! 
Hey Rooney, nice shot 
I thought maybe you’d done some research like I had several years ago to find out why one of my most coveted Japanese plum trees hardly sets any fruit (Burbank Red Ace)… Then found out that Luther Burbank had been crossing them with the equivalent of their parents and siblings. Sure, the resulting fruit can be amazing, but finding a pollinator has been near impossible.
So, after doing loads more research I learn of a compatible combination not so closely related (and blooming at the same time), procure a stick or two from our scion exchange, graft them around the orchard… and wait. Hopefully ‘this’ will be the year – but maybe not?
With regard to pollinating insects, check out the night-time activity, too. I was amazed one night by the activity of small moths and friends ‘working’ a plum tree by moonlight! Gave me an additional perspective on pollination. So, as I’d been drilling countless holes in wooden blocks to house Mason bees …the real action may have been occurring at night 
Not far from my hometown of Portland, I hope to get at least a half-decent set on my Japanese plums (Satsuma & Shiro), cuz if I were to only have one fruit tree, that combo would likely be it. That said, and at a slightly higher altitude, mine have yet to bloom …leaving the chance the sun might reappear just in time …cuz the moon’s almost gone 
I do lots of research and head-starting of projects of what I get from the internet too Viron. As I always end up taking care of property in interior Alaska I'm always finding new ways to dry and bring pollens with me there every spring. One year I ended up bringing some pollen of wild Hunza apricot (a pollen gift to me by a breeder) and it took pretty good care of a plum crop in Alaska for another friend up there.
It was so much fun to see lots of new fruit way up there but a bit disappointing to see not many stones germinated from that, but a couple did. Then died of a transplant shock so never really knew if the hunza pollen facilitated a selfed (inbreeding depression) cross, or not.
It's all very technical stuff which is almost too much to talk all about considering inbreeding depression might be only part of the key to it all. But this one thing I know from several sources, my own experiences, and you included, that your chances of getting good pollen will always be from non commercial sources. This is probably true not only for plums but maybe cherry too, which is why I want to test the pictured pollen of this zakura before commending it as "the possible" pollinator for my unproductive early burlat.
This Zakura I'm testing I have noticed already anthesis is happening before the blossoms open. Which is very unusual but handy when it rains you only have to pick them before they become moisture logged and take charge yourself setting it on wet cherry blooms. I will post back on the happenings of Zakura male once cherries are established down the road or another thread, so GO ahead with public comments, pollen (or otherwise camera).
Idyllwild
simplepress
jafar
Marsha H
Viron
John S
1 Guest(s)