I've pasted my recommendations from another thread I posted on last week
medinose has completely cured me, it works using red light waves to densitise the nasal membranes. You are supposed to use it twice a day, but after a couple of weeks last summer I used it once every two days. it may be worth shopping around - they do have a money back guarantee or look at the Lloyds pharmacy version.
Other things that may help:
buy a plant spray from the garden centre/diy shop, fill with water, put onto a fine mist setting and spray over yourself, his clothes, the furniture, around the windows, pets etc.
you don't get hayfever when it rains, it helps to make the air as damp as possible.
Another thought is have you heard of neti pots?
Its washing the nose out with very warm water and a little salt. This washes out the pollen.
nasopure is the most poweful one.
If you don't like the look of these you could go to your local chemist and ask for sterimar
Coat inside of nostrils and eyelashes with vasaline or balm as this helps trap the pollen
failing all of the above have a shower including hair wash and change clothes
I'm a bit of a hayfever bore having suffered for nearly 25 years, my ds2 has got it now so I'm really into doing this naturally and find all of the above work better than any conventional medicine including all the tablets, sprays, steriod injections. I've also tried acupuncture which worked for one year and not the next, homeopathy and very local honey (both used before the season started) both were a waste of money.
Best of luck, I know how debilitating it is, I even wore a dust mask one year as I couldn't sneeze and drive at the same time!