This answer can vary form person to person depending on your sensitivities.
Here are some great articles: http://www.nutriliving.com/blog/dealing-food-allergies
Focus on cleaning out toxins/irritants with "binders" like chia seed, parsley, and aloe. Adding bee pollen as a supplement has been shown to benefit w/ allergy symptoms (as long as you are not allergic to pollen). You could even try adding a neti pot for nasal irrigation. Make sure to talk to your doctor about any of these issues and changes.
Check out this article and supplement recommendations such as butterbur, quercetin, and bromelain from Dr. Sarah Gottfried:
These additional food tips can help reduce seasonal allergies:
* The flavonoid compound quercetin aids in controlling histamine reaction which is what causes an allergic response. Quercetin can be found in black plums, cranberries, and blueberries.
* Omega-3's aid in combating inflammation which is what causes the stuffy effect. Flaxseed oil contains an abundance of omega-3's.
* Increase your Vitamin C intake to give your immune system that extra punch when it's trying to fight off an allergic reaction. Kale is a great source of Vitamin C.