Online Staff Report
Many are suffering from sneezing and sniffling as a result of allergies. Although some are quick to blame the lovely, yellow blooming goldenrod, the culprit is really ragweed, according to University of Illinois horticulture educator Candice Miller.
Ragweed is flowering in northern Illinois, releasing its lightweight pollen grains into the air by the millions. Each ragweed plant can produce an estimated 1 billion pollen grains.
In Illinois, you’ll find two types of ragweed, both native annual plants; common ragweed (Ambrosia artemisiifolia) and giant ragweed (Ambrosia trifida).
Common ragweed is indeed common along roadsides, cultivated fields, vacant lots and pastures. It grows 1 to 4 feet tall with densely hairy stems and deeply lobed (almost ferny) leaves. Common ragweed grows well in gravelly areas along roads where it thrives under abuses that would knock out most plants.
Giant ragweed is a larger version at 13 to 15 feet tall. Its coarse, rough stems hold large, slightly hairy leaves that grow almost a foot long with three or sometimes five pointed lobes. Giant ragweed can be common in cultivated fields, fence rows, roadsides and unmown construction sites.
Since ragweed is an annual weed, the key to controlling it is getting to the plants before they set seed. Get plants removed as early as possible this fall, and be sure to remove any next season as well before they flower.
Gardening during allergy season can be a challenge. Weather conditions can make a difference in the pollen levels. The most favorable conditions for high pollen are warm and dry, while high humidity and rainfall lessens pollen release. Also, the time of day can influence pollen levels. Pollen release is highest in mid-morning after dew has dried.
If you’re an allergy sufferer and go outside during the worst times for pollen levels, horticulture educator Sandy Mason recommends reducing your exposure by wearing gloves, a long-sleeved shirt, hat and sunglasses or goggles. A pollen mask may be necessary. After working outside, take a shower and thoroughly wash hair and clothes. Look forward to October. Ragweed allergy season generally lasts through September.
Need help identifying ragweed? Drop a sample off to the master gardeners at your local extension office and they can help you identify it.
Posted Sept. 4, 2013