We know that being out in nature is a major stress reliever. Studies show that breathing in the scent of fresh greenery lowers levels of the stress hormone cortisol by 12%. And that allows us to think more clearly. But what if you have allergies – and inhaling the scent of trees and grass makes you a wheezing, watery-eyed mess? Get fragrant houseplants – like a eucalyptus or wax plant. Research from the University of Michigan found that inhaling those scents improves attention span and focus – and even raises people’s scores on language and memory tests. An added bonus? Those plants also purify indoor air from allergens.