Do You Have Allergies? Do You Have Allergies?
National Insitute of Asthma, Allergy and Immunology

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Pollen
Ragweed Pollen
Grass Pollen
Tree Pollen
Ragweed Pollen
Ragweed and other weeds such as curly dock, lambs quarters, pigweed, plantain, sheep sorrel and sagebrush are some of the most prolific producers of pollen allergens.

Although the ragweed pollen season runs from August to November, ragweed pollen levels usually peak in mid-September in many areas in the country.

In addition, pollen counts are highest between 5 – 10 AM and on dry, hot and windy days.

Preventive Strategies
Avoid the outdoors between 5-10 AM. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.

Grass Pollen
As with tree pollen, grass pollen is regional as well as seasonal. In addition, grass pollen levels can be affected by temperature, time of day and rain.

Of the 1,200 species of grass that grow in North America, only a small percentage of these cause allergies. The most common grasses that can cause allergies are:

Bermuda grass
Johnson grass
Kentucky bluegrass
Orchard grass
Sweet vernal grass
Timothy grass

Preventive Strategies

Specifically:

If you have a grass lawn, have someone else do the mowing. If you must mow the lawn yourself, wear a mask.
Keep grass cut short.
Choose ground covers that don’t produce much pollen, such as Irish moss, bunch, and dichondra.
In General:

Avoid the outdoors between 5-10 AM. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.
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Tree Pollen
Trees are the earliest pollen producers, releasing their pollen as early as January in the Southern states and as late as May or June in the Northern states.

Trees can aggravate your allergy whether or not they are on your property, since trees release large amounts of pollen that can be distributed miles away from the originial source.

Of the 50,000 different kinds of trees, less than 100 have been shown to cause allergies. Most allergies are specific to one type of tree such as:

catalpa
elm
hickory
olive
pecan
sycamore
walnut

or to the male cultivar of certain trees. The female of these species are totally pollen-free:

ash
box elder
cottonwood
date palm
maple (red)
maple (silver)
Phoenix palm
poplar
willow

Some people, though, do show cross-reactivity among trees in the alder, beech, birch and oak family, and the juniper and cedar family.

Preventive Strategies
If you buy trees for your yard, look for species that do not aggravate allergies such as crape myrtle, dogwood, fig, fir, palm, pear, plum, redbud and redwood trees or the female cultivars of ash, box elder, cottonwood, maple, palm, poplar or willow trees.
Avoid the outdoors between 5-10 AM. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.