Lawn Weeds & Allergies AlinaMD / iStock / via Getty Images Weeds in the lawn can hamper grass growth, but for millions of Americans who suffer from allergies, more of a problem is that they’re a nearby source of breathing trouble. An estimated 40 to 50 million U.S. adults are prone to allergic rhinitis – better known as hay fever – according to the American Academy of Allergy, Asthma, and Immunology. Pollen from plants is a leading hay fever trigger, causing symptoms such as sneezing, stuffy or runny nose, watery eyes, scratchy throat, coughing, and asthma attacks. Pollen is a fine powder that trees, flowers, grasses, and weeds produce when they flower. When sensitive people breathe in that powder, their immune systems treat pollen as a harmful intruder and spring into action to expel or neutralize it. Some people are allergic to just one or a few types of pollen and react seasonally when the offending plants are in flower. Others have broader allergies that make going outside a problem most anytime throughout the growing season. White Dandelion BrianAJackson / iStock / via Getty Images Which weeds are the worst offenders? Although it’s impossible to eliminate every tree or flower that could trigger allergic reactions, it is useful to control some of the worst offenders that we don’t want anyway. By pulling, killing, or preventing weeds that flower, at least those sources of airborne pollen can be reduced. According to the Weed Science Society of America and PollenLibrary.com, some of the worst allergy-causing grassy weeds in lawns are annual bluegrass, barnyard grass, dallisgrass, foxtail, johnsongrass, orchardgrass, quackgrass, and velvetgrass. Some of the worst broadleaf weeds for allergy sufferers are dandelion, dock, Kochia, lambs quarters, mugwort, nettle, pigweed, plantain, Queen Anne’s lace, red and sheep sorrel, sagebrush, wormwood, and the king of sneeze-inducers, ragweed. The pollen grains in some of those weeds are so small and buoyant that they can be carried in the air for hundreds of miles. Young Boy Sneezing Kontrec / E+ / via Getty Images How to ease the sneeze Since pollen is the problem, allergic reactions can be avoided by making sure offending plants never go to flower. That’s possible for some grasses and lawn weeds by frequent and close mowing. However, too-close mowing is counter-productive for good turfgrass growth, plus some plants are so short or produce flowers so quickly that it’s difficult to keep a lid on their flowering. A better option is to remove or kill weeds before they have a chance to flower. That’s easier for broadleaf weeds in the lawn because they’re different enough botanically from grassy plants that a variety of herbicides can kill them without harming turfgrass. GreenView Broadleaf Weed Control plus Lawn Food with GreenSmart and GreenView Weed and Feed, for example, are two granular products that contain three herbicides that together kill more than 250 weeds, including top sneeze-inducers such as dandelion, dock, Kochia, lambs quarters, mugwort, nettle, pigweed, plantain, and ragweed. Grassy weeds are better controlled by preventing them from sprouting in the first place. GreenView Crabgrass Control plus Lawn Food with GreenSmart stops crabgrass and 16 other grassy weeds in addition to controlling 23 varieties of broadleaf weeds and fertilizing for eight weeks. And for those who want to control crabgrass, kill weeds, and fertilize at the same time, there’s the three-in-one GreenView Fairway Formula Spring Fertilizer Weed and Feed and Crabgrass Preventer that prevents eight grassy weeds, kills more than 200 broadleaf weeds, and fertilizes for up to 12 weeks. Larger weeds also can be hand-pulled or dug out of lawns using a narrow weeding tool or even a screwdriver. Some other allergy-fighting strategies include staying indoors when pollen levels are highest, wearing a dust mask when mowing or working in the yard, and discussing over-the-counter and prescription medications with your doctor. Allergy shots also are available to lessen allergy reactions in particularly sensitive people.