New Allergy-Risk Scale Developed for Plants

With some tree and shrub species, whether you specify males or females can make a huge difference for allergy sufferers. This point is one of the most intriguing to emerge from recent work of Thomas Ogren, a San Luis Obispo, California-based expert on flowering plants and pollen-related allergies. Ogren has developed an innovative scale of the relative allergy risk of common landscaping plants— information that will be published next month in his book

Allergy-Free Gardening (Ten Speed Press). He first became interested in the relative allergy risk of different plants in the 1980s because his wife suffered from severe asthma and hay fever. Researching which plants were most appropriate to install for low allergy risk, he was surprised to find almost nothing written on the subject. He devoted the next fourteen years to the question and, in the process, developed the Ogren Plant Allergy Scale (OPALS™).