I spend considerable time watching my mason bees, and I note that they don’t come out to work when the temps are under 50 F. This makes me wonder if the bees are reacting just to the cold, or is the pollen somehow involved? If the bees know that the pollen won’t be good at low temps, might they not harvest it then?
I know that pollen tends to lose viability at extremely high temps. Could something similar be going on at low temps? And does this mean that if the bees aren’t working the flowers, would it be futile for me to try hand pollinating?
It’s futile to try hand pollination if the flower isn’t shedding pollen. Just because the bees aren’t flying doesn’t mean the pollen isn’t viable for pollination or isn’t good food for their young. And I think the bees don’t fly below a certain temperature because they are too cold for their muscles to function properly.
But does cold weather retard the flower shedding pollen - or developing it? The flowers that hang and hang on the tree in cold weather - are they waiting for conditions to create pollen, or to be pollinated?
It seems that I am in the same boat as you were in 2016. In the past week or so, highs were around 45 and lows around 35; my Pluot blossoms started opening, but they are shedding zero pollens… I am also not seeing any bees. Tomorrow and the following few days we’ll have highs in the seventies and high sixties, so I’ll be checking the new blossoms for pollen to be able to tell if it it’s the temperature that prevented the release of pollens from the anthers or previous cold waves killed the pollens when the buds were swollen.
I didn’t know you were that cold. You won’t get pollen at those temperatures. When it warms up things will improve. After a while you’ll notice the changes that occur in the flower as the anthers mature and shed pollen. Then you can work the flowers that are shedding. That was my plan, work the flowers shedding and thinking they were also still receptive. It seemed to work. No sense working flowers not shedding or past receptive.