III - Yup, summer too. It brings out the sap like crazy. I think it might have to do with heat stress on the trees, although I'm not sure. I may have to research this. However, when Sept. rolls around I find that the sap stops.
Anyway...we have oak trees on the property and all summer long they drop little droplets of sap. When I pull in the driveway to open the garage door by the time I get back in the car there's droplets all over the windshield! It's unreal. I wear glasses and I can even see the stuff on my lenses !!!
I think that Pine tress are the worst culprit dropping very large drops that are very difficult to remove if left on too long.
I wonder if there are any tree experts out there who can shed some light (no sap please !) on this subject???