Easy. Skin testing for pollen allergy entails: cleaning the skin with alcohol, number the skin to keep track of the different allergens tested, a "prick" with skin test device that has a drop of the allergen on the tip and then waiting 15-20 minutes to see if a reaction occurs. The skin test feels like a mosquito bite it is really quite painless.
Do sweet gum and hackberry trees have pollen? My allergy test tested positive with a 3. Rated on 0-6 scale
Every tree does. Every tree is going to have to have pollen. Do they reproduce?