June 3, 2011 -- A pair of towering male junipers once flanked the door to historian Dan Krieger's home office in San Luis Obispo, CA. The blue-green boughs extended 20 feet in the air--and, unbeknownst to Krieger, silently released clouds of sneeze-provoking pollen. "I felt terrible," he says. "I took lots of antihistamines while working in my office. But I never suspected those trees."
Krieger's brother-in-law, the well-known horticulturalist Thomas Ogren, did. He persuaded Krieger to replace the male junipers with yew and other low-allergy alternatives--with dramatic effect.
"I feel great now," says Krieger, a professor at California Polytechnic State University. "I don't sneeze or need antihistamines, and I'm more productive."
Ogren, who has a master's degree in agricultural science and is the author of Allergy-Free Gardening and a related book, Safe Sex in the Garden, isn't surprised. Drawing on 2 decades of research into the allergenic potential of plants, he developed an allergy ranking system--the Ogren Plant Allergy Scale (OPALS)--for more than 3,000 common trees, shrubs, flowers, and grasses.
The junipers he advised Krieger to remove ranked a scale-topping 10; the replacement yew, a sneeze-free 1. Ogren also prevailed upon Krieger to remove coyote brush (another 10) from around the house. For the first time ever, Krieger's wife, who has both allergies and asthma, was able to enjoy the yard.
First Steps toward Sneeze Reduction
A recent report by the American Academy of Allergy, Asthma, and Immunology estimates that as many as 36 million Americans have seasonal allergies. If you're among this tissue-clutching set, you, too, can enjoy your yard. Replacing an exceptionally allergenic shrub or tree with a non-sneeze-provoking variety, as Krieger did, can work wonders. But there are far simpler tactics to try first. Start with these:
Mow low. Trim the lawn more often to keep it short--about 2 inches--and you'll lop off the tops of those leaves of grass before they produce flowers and pollen. Note: If you have particularly bad allergies, ask someone else to mow.
Crowd out the worst offenders. Fertilize your lawn to grow thick grass that chokes out highly allergenic weeds such as nettle, annual bluegrass, and dandelion.
Pick the right time for yard work. Pollen levels are highest on warm, dry, windy days. Good times to get down and dirty among the flora: after a long, soaking rain or when the pollen index for your area is low. But wait an hour or so after a dramatic storm. "Hard rain fractures pollen grains, exposing more of the proteins that prompt allergic reactions," cautions Richard Weber, MD, a professor of medicine at National Jewish Medical and Research Center in Denver and a leading expert on pollen allergy.
Protect your skin. When possible, wear long sleeves and pants while gardening, cutting grass, etc. If you're allergic to the pollen that touches your skin, it can cause swelling, redness, and rashes.
Wear big shades and carry saline eyewash. If pollen comes in contact with your eyes, it can make them itch and tear.
Clean yourself up. After finishing with the flower beds and lawn, change your clothes at the door, and then shower and wash your hair to rinse away any pollen.
Experiment with meds. Try an over-the-counter antihistamine if the above measures don't do the trick. Still no relief? Ask an allergist about allergy shots. "They work for 90% of people," Weber says. The downside: Shots can be costly and time-consuming (one or two per week for up to 6 months, followed by regular maintenance injections).
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If nothing works and you don't want to try shots, consider Ogren's approach--replacing egregiously allergenic plants with less or nonallergenic ones. The theory behind his strategy: The pollen that's making you miserable is probably coming from your very own flora.
Sure, pollen can waft from your neighbor's towering birch tree into your yard. But most doesn't fall or float far from the tree (or shrub or flower). In one Dutch study, levels of birch and oak pollen were consistently highest closest to the trees.
To determine whether to axe an offending plant, follow these steps:
See an allergist. If you haven't already, get tested to find out if that elm or rose bush really is at the root of your misery. Ask the allergist about cross-reactions, Weber suggests. If you're allergic to birch pollen, for example, you may also react to alder, beech, hazel, and oak pollen.
Check your yard for allergy triggers. Now that you know what you're looking for, see if the culprit is in your yard. If you can't identify a tree, shrub, or flower, take a cutting to a local nursery or to your county's Cooperative Extension Service (find your local agent at www.csrees.usda.gov). "Or call a local college with a horticulture program, and pay a student to ID what's growing on your property," Ogren suggests.
Replace with care... If you've decided to remove a plant, choose a female replacement of a variety that doesn't trigger your sneezing. Male plants are the ones that produce pollen. (Staff at your local nursery should be able to distinguish one sex from the other.) Also, opt for a variety that ranks low on the OPALS scale (find it at www.allegra.com) because these plants are least likely to cause allergic reactions in others, including your partner, kids, guests, and neighbors.
...Or pay for a sex change. Got a stately male tree that's just too allergenic to keep? You don't have to settle for a spindly new replacement. A skilled nurseryman or arborist should be able to graft branches from a female tree onto the existing tree. In one season, the tree will change from a highly allergenic male to a pollen-free female. Expect to pay $50 an hour; a typical tree can be grafted in an hour or two.
Change Your Landscape
Making adjustments to the layout of your garden may be unavoidable. Here are some tips for how you can create a new allergy-free environment:
Load up on low-allergy plants. If you've got pollen allergies, your best bets are:
Flowers: Begonia, crocus, daffodil, iris, poppy, tulip, camellia, clematis, hollyhock, impatiens, nasturtium, pansy, peony, fully double sunflowers, zinnia
Trees and shrubs: Azalea; dogwood; fir; fruit trees such as peach, plum, pear, persimmon; female versions of ash, Chinese pistache tree, female juniper, yew, yew pine, poplar, box elder, some maples, sour gum, willow
Keep mold at bay. Because mold can cause allergic reactions, keep compost bins--a prime mold habitat--away from the house and garden.
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