An excerpt of an article which appeared in the WSJ 9/24/2013
By Anne Marie Chaker
People hoping that the approach of autumn will mean fewer allergy symptoms, may want to prepare for some sneezing with their leaf-raking.
For many people, allergic reactions go into overdrive late summer and into fall because pollen counts soar. Mold counts rise, too, thanks largely to wet leaves sitting on the ground, a terrific breeding situation for mold spores.
While many popular garden plants are insect-pollinated—often with showy flowers that attract pollinators, and bearing heavier, stickier pollen grains—it is the wind-pollinated plants that cause the most problems for allergy sufferers, says Susan Littlefield, horticulturist for the National Gardening Association.
Plants such as ragweed, grasses and certain trees have small, inconspicuous flowers that produce clouds of tiny, light pollen grains that can blow away for hundreds of miles. Weeds and grasses are big fall offenders, while tree pollen tends to emerge in the Spring.
Ragweed of various types can be found most anywhere in the U.S., says allergist Richard Weber, president of the American College of Allergy, Asthma and Immunology, based in Arlington Heights, Ill. It is most ubiquitous along the East Coast (Common Ragweed or Ambrosia artemisiifolia) and in the Midwest (Giant Ragweed or Ambrosia trifida). Sage brush is a big fall-season pollen producer in more-arid Western states such as Colorado, New Mexico and Utah, he says.
Ragweed is one of the main culprits of hay fever, or allergic rhinitis, which affects as many as 15% of adults and children, says the allergy group.
There are a few considerations to help keep the sniffling and sneezing at bay.
Timing: Avoid gardening in the afternoon, when pollen counts are at their highest, says the association. Opt for early morning and evening hours.
Weather: A light rain can temporarily clear pollen from the air, making the aftermath of a rain shower a good time to garden—not to mention making it easier for pulling weeds. Thunderstorms, however, can increase airborne allergens. The force of the wind and rain breaks apart pollen grains to release more allergenic particles. The standing water left behind is also the perfect breeding ground for mold spores.
Dressing: Gardening gloves keep hands clean, sunglasses or goggles help keep pollen and mold from aggravating your eyes and a hat can reduce pollen sticking to your hair. If you opt for a mask, find one rated N95 by the National Institute for Occupational Safety and Health, advises Dr. Weber, rather than a simple dust mask which can have openings on the side that let air sneak in. While the heftier masks do a better job, they can also overheat the face. “You’re miserable from having this hot thing on your face, but you’re relieved of your runnies and itchies,” he says.
If all this makes you want to avoid yard work, know that mold and pollen can collect on fallen leaves, so experts recommend regular fall yard maintenance .
A big offender: The fruitless mulberry tree, which in recent years has been showing up in municipal plantings across the country and in school landscapes. “They grow fast, they’re a nice shade tree,” Dr. Weber says. “But they produce billions of grains of the most allergenic pollen.”
Ms. Littlefield of the gardening association notes that “Shrubs and flowers with large or colorful flowers are good choices for allergy sufferers, as are most herbs, vegetables, and fruits,” she says. Roses, daffodils and sunflowers are other safe bets.
“Many deciduous trees, as well as most evergreens and grasses, including ornamental grasses, are wind pollinated and potentially allergenic.”
Tree species that are insect pollinated, rather than wind pollinated, and perhaps better choices for allergy sufferers include dogwoods, magnolias, and fruit trees such as apple, cherry and plum.