The main cause of hay fever from now on in large areas of the US is ragweed. I agree about the rag weed pollen but here in the southern USA the bees gather ragweed pollen and nectar form late July until other sources of pollen and bedime available in late August or early September. The reason for the 50 mile radius. Is probably an arbitrary figure, but the idea is for a person to get honey that contains pollen form most sources that a person is likely to encounter locally. There is a reason that we have a lack scientific fact about the use of natural treatments for many things and allergies being one of them.
Money is spent , where money can be made.
You will see very slow progress in natural cures , but we all know that they are out there. We get most of our medicine from plants in the first place, but we have to support a very large industry for us to get it to our mouths. I'm not against medicine , but I'm against the way we are hand fed to believe that it is the only way. We could have more than pollen in unstrained, unheated honey, that has a positive affect for us on allergies. I have Doctors that buy honey from me and only want raw honey.