I'm thinking only about a week or two? There seems to be more of it this year than I can remember, but maybe I say that every year!!!
There is more of it this year.....the trees are bigger.
Seriously, I think this on and off winter/spring that we had slowed things down and everything dumped their pollen during a shorter period of time to get ready for summer. "They" say that heavy pollen falls mean more acorns and pine cones for the squirrels to lay up nuts and seeds for a cold, cold winter. In zone 8b/9a, the pines seem to be finished and the oaks just getting started.
I think the pollen usually lasts for 2-3 weeks, or until we get a really good, hard rain...I'm praying for rain for that reason, along with the fact that my plants need it!
They said on tv this is a real bad year for pollen with the lack of rain and more importantly the lack of late freezes.
This is such a great time of year for car wash businesses I bet.
And don't forget the antihistamine business too, all the sneezing, eye watering, and coughing.