natural allergy remedies?

My allergies are always so bad... especially this time of year. The only thing that I know that I'm allergic to is trees. I've tried every type of nasal spray, puffer and pill but none work. I asked my doctor if I could get the allergy shots but she said in order to get those, you need to know specifically what you are allergic to and since I don't know what exactly I'm allergic to (trees but something else is causing my allergies right now because trees aren't blooming), so I can't get the shots. Since none of the allergy medications seem to work, I was thinking of trying a natural approach. Does anyone know of any natural remedies that work good for allergies? I am always so stuffed up and sneezing all the time and sometimes have trouble breathing because of it. I'm willing to try anything at this point! The sneezing I can live with, it's the constant stuffed up and runny nose that drives me batty!! It's like this ALL year round! It's like I have a permanent cold that won't go away! Except I'm not sick, it's just really bad allergies. Any tips or advice on any home remedies that I can do to help improve them?

Thanks!