Grass Pollens Begin Second Phase of Allergy Season

Once the tree pollens have kicked off the spring allergy season, it’s time for phase two of nature’s three-step pollination cycle to spring into high gear. The allergen waiting in the wings? Grass pollen, the primary cause of spring and summer hay fever attacks, or seasonal allergic rhinitis.

While the seasonal allergy cycle begins and ends at different times around the country – lasting as long as from January to November in southern climates – nature’s pollination pattern traditionally follows the same three phases: trees, grasses, then weeds.

During the fertilization process of these plants, lightweight airborne pollens are released and transmitted by wind to other plants. When these generally harmless substances are inhaled by those who suffer from seasonal allergic rhinitis, the body may experience an “overreaction” of the immune system. Once the body recognizes the pollen, the immune system goes to work, causing the tell-tale outward symptoms, including sneezing, congestion, runny nose, watery eyes, and itching in the eyes, nose and throat. Asthmatics may experience tightness in the chest, a hacking cough and difficulty breathing.

Some of the most common allergy-causing grass pollens include those from Timothy, Bermuda, Bahia, Orchard, Sweet vernal, Red top and some blue grasses. Bermuda and bahia grass is responsible for allergies nearly year-round here in the south. A well manicured lawn or golf course generally does not produce much grass pollen. The offending grasses primarily grow in medians and sides of roads as well as empty lots. These pollens are very light and are blown for miles, so you do not have to be in close proximity of them to have problems.. St. Augustine grass, the most common lawn grass in the Houston area, is not allergenic because it propagates primarily by sending out crawlers. The pollen it makes is very heavy and falls immediately to the ground. When people have problems mowing St. Augustine grass it may be due to exposure of other grass pollens that are in the air or from molds which are stirred up while mowing.

As with other plant pollens, rain and temperatures may affect the amount of pollen produced each year. Peak pollen release is during early to mid-morning hours. Dry, windy days are optimal conditions for high pollen counts.

Houston-area pollen counts provided by the City of Houston Health Department detect grass pollen year round. While those counts are low to moderate throughout much of the year, during March the count begins to climb. By early May, grass pollen counts are peaking, tapering off by June or July. *In the Houston area, low grass pollen counts are from zero to five, moderate from six to 20, high counts from 21 to 200, and very high counts those above 201.

To minimize suffering during grass pollen season, following are some allergen avoidance tips:

  • Keep the grass short, but have someone else do the mowing. If you can’t avoid yard duty, wear a mask as you mow.
  • Don’t hang clothes outside to dry – pollen bonds to fabric.
  • Stay indoors in the early morning hours between 5:00 and 10:00 a.m. when pollen counts are highest. Save outdoor activities for late afternoon or after a heavy rain.
  • Shower and shampoo frequently to wash pollen out of your hair.
  • Keep your home and car windows closed to prevent airborne pollens from coming inside. When riding in your car use the recycled air button on your air conditioner.

If you suffer the symptoms of seasonal allergic rhinitis, your first course of action should be an accurate diagnosis by a board-certified allergist/immunologist. From there, appropriate treatment options can be determined. Antihistamines, decongestants and steroid nose sprays are available by prescription to reduce or alleviate immediate allergy symptoms. Long-term relief is available through allergy shots or immunotherapy, a process that involves injecting extracts of the offending allergen in gradually increasing doses to reduce the body’s sensitivity over time.

For up-to-date information on local and national grass pollen counts follow the links at the bottom of our Home page.

* Pollen & Mold Counts for Texas, 2nd Edition – 1997.


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