Tuesday, September 23, 2014

Got allergies? Don't blame the goldenrod!

It's mid-September and the goldenrod is now in full bloom -- right about the same time that the pollen count hits the roof.  Over and over, I hear people blaming their hay fever on goldenrod.   But they are wrong!  Read on...

A field of goldenrod on my land in Minnesota --
haven for many butterflies & other insects
 Everyone can see the bright yellow of a field of goldenrod plants in full bloom.  As they look at all those yellow flowers along the road, they visualize clouds of pollen choking the air.  Just the sight of it all is enough to make some people sneeze.

But the fact is, goldenrod pollen is not spread by the wind at all.  This is why weather reports that include a pollen count never even mention goldenrod as a source.

A Goldenrod flower
Don't believe me?  See for yourself: Touch a goldenrod flower and you will not have any pollen on your hands.  Shake one and you won't see any clouds of pollen hitting the air.  It just doesn't blow around.   It spreads by sticking to the bodies of insects.  Unless you are a bug with lots of tiny hairs on your body to pick up the pollen, it doesn't leave the plant very easily.  Ecologically speaking, Goldenrod is an important nectaring flower for wasps, bees, butterflies, and other beneficial insects.  So please -- don't yank it out!

Ragweed plant in full bloom
The real culprit is ragweed, a coarse weedy green plant that blends into the background in fields and woodland edges.  Unlike the showy flowers of goldenrod, the rather nondescript flower stalks of ragweed are just loaded with pollen, and it does indeed spread on the wind.

Ragweed is not particular about habitat, and will grow just about anywhere.  The plant in this photo grew next to my compost pile, so it got to be over 6 feet tall from all that rich chicken manure.  Along the road you might see flowering ragweed only about a foot high, eking out an existence in the hard-packed gravel on the shoulder.  But once you learn to recognize it, you'll see it growing just about everywhere.

(Well, maybe not in the high desert -- but it crops up in irrigated areas like Las Vegas.  In fact, according to The 30 Worst Cities for Ragweed, Las Vegas ranks #2.  The top city on the list is Phoenix, Arizona.)

The stuff is very easy to pull up, so if you learn to to recognize it before it pollens out, you can at least eliminate it from your garden.  But with all the acres and acres of wild areas where it can flourish, you will probably have to wait until frost kills the plants before your "hay fever" finally goes away for the season.  Just don't blame your misery on the innocent goldenrod!

Typical distribution of ragweed pollen in
the USA in September

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