Just listened to a guy on a podcast (Thomas Ogren) talking about allergies and gardening. I highly recommend listening. This guy knows his stuff. I learned a lot regarding pollen etc, which is of course a big part of what we do.
I like listening to Patrick Timpone's podcasts generally anyways.
http://oneradionetwork.com/healing-modalites/thomas-ogren-the-allergy-fighting-garden-june-29-2015/