2013 is the year of the Wild Plum, (Prunus americana)! Yields were prolific, bending branches with the weight of the juicy orbs. I ate my fill, yet the pulp of fallen plums squished underfoot.
I wonder why it was such a good year. I know the weather at flowering in the spring is a large factor. It must have been perfect this year. The wild apples were the best ever as well.
What other factors affect yield? I read that drought reduces yield for plum trees. Last year we had a severe drought until August. This year our drought started in July, following over-abundant rains.
My theory is the plum trees suffered early last summer, but were then recharged with the late summer 2012 and early summer 2013 rain, resulting in huge yields. I’ll have to wait and see if next year’s yield is affected by this year’s drought.
Curiousfarmer 
Is someone making jam?
Unfortunately no. I’m better at finding and eating than I am at preserving. If our current way of life ever changes whereby I can’t buy Brazilian grapes and California tomatoes in March, I’m thinking I’ll need to preserve so I can have a taste of summer in winter.
http://www.gregbrown.org/gbonent1.html#cannedg
Check out the lyrics for “Canned Goods” by Greg Brown.
2014 was a terrible year for plums.