The American Lung Association recommends that low allergy trees be plantedin order to avoid triggering asthma or allergy episodes.The trees listed have a rating of less than 4 on the OPALS scale developed by Tom Ogren, author of Allergy-Free Gardening.The OPALS scale takes into account the method of pollination, plant family, size, fragrance, length of pollination time, and other pollen factors.Also, The trees on this list have been reviewed by a local nursery in order to ensure that these trees can thrive in the Imperial Valley’s climate and soil.The following two trees meet the OPALS requirements and have been recommended by a local nursery for Heber soil:
Jacaranda (Jacaranda Mimosifolia)
Raywood Ash (Franxinus oxycarpa, F. augustifolia)
The following three trees meet the OPALS requirements and have been noted by a local nursery as being able to thrive in this region:
