2. Bermuda grass
3. Maple tree, especially the ashleaf maple
4. Mountain cedar tree
5. Rye grass
6. Elm tree
7. Mulberry tree
8. Pecan tree
10. Oak tree
Source: The Learning Channel
Bradford pear trees have been getting a bum rap.
Lovely Bradford pears -- fluffy in white flowers each spring -- often take the blame from allergy sufferers for igniting fits of sneezes.
But Vanderbilt professor Robert Valet says that contradicts a relatively unknown adage: The uglier a flower or weed, the more allergy-inducing its pollen tends to be.
"That's true," agrees Dr. Marc Cromie at Chattanooga Allergy Clinic. "Flowers that are very colorful and beautiful, their pollen is nonallergenic. The reason they survive is that bees are attracted to them, and bees carry the pollen from one flower to another."
The allergist explains that ragweed and trees such as pine, oak, hickory and pecan are not very colorful.
"They are reproduced through tiny pollen granules that are windborne. That's how they survive. Their pollen is so small and microscopic that it gets in the air and we breathe it in," he says.
Sneezing and runny noses soon follow.
Valet says allergy season can be divided into spring, summer and fall, running roughly from March to October.
Trees are spring's allergen triggers; oak, maple, walnut, pecan and hickory among the worst offenders. In summer, tree pollens are dying out, but grass pollen is on the rise, says Cromie.
"The summer pollen species most people are allergic to are fescue, Timothy, Bermuda and Johnson grass," he says. "At Chattanooga Allergy Clinic, we check for 10 grasses that are known allergens."
Valet, assistant professor of medicine and an allergist at Vanderbilt University Medical Center's Asthma, Sinus and Allergy Program clinic, says ragweed, mugwort, plantain and pigweed are "some of the worst offenders to allergy sufferers."
Ragweed -- that lacy green-yellow weed that grows wild in fields -- can produce up to 1 billion pollen grains per plant throughout its pollen season, says the Asthma and Allergy Foundation of America. Of people allergic to pollen-producing plants, 75 percent are allergic to ragweed.
"Plantain is in your grass -- almost everybody has it in their yards," says Beth Painter, who owns Green Thumb Nursery in Hixson with her husband, Ray.
Plantain is in no way related to the banana-like fruit pronounced the same way. This allergen from the Plantago genus is a broad-leafed weed with a flowering spike shooting out of the center of the base. Tiny white flowers bloom around the top half of the spike.
"It looks like a funky clover, and it smells sort of onion-ish when you cut the grass," Painter says.
"It won't just go away. You have to kill it, or you can go in and dig the roots out and put the weed in the garbage. But if you dig the roots out, lots of times that will spread it, cultivate it," she adds.
Painter recommends spraying plantain with Weed Free Zone by Fertilome for best results.
At what point should a person quit trying to treat their watering eyes, stuffy noses and sneezing with over-the-counter medicines and see an allergist?
"Typically, patients who have symptoms lasting more than a couple of weeks," says Cromie. "People who are getting secondary sinus infections, asthma flare-ups, stuffy noses at night that prevent sleep. They need to see a board-certified allergist who can figure out what they are allergic to and start treatment."
Contact staff writer Susan Pierce at spierce@timesfree press.com or 423-757-6284.