It’s late summer and your eyes have become itchy and watery. Your nose is running and stuffy because you’ve been sneezing like crazy. There must be some pollen in the air wreaking havoc with your respiratory system! You look around and see many bright yellow goldenrods in the fields and along the roadside so naturally you assume these are the culprits. WRONG!
Goldenrod often gets a bad rap because it blooms (very conspicuously) at the same time as ragweed – the real pollen factory at this time of year.
Ragweed is a common weed that blooms in August and September with spikes of inconspicuous greenish flowers. If you look around where colorful yellow goldenrods are blooming, you will probably also see large stands of ragweed – they are just not as noticeable because they don’t have showy flowers.
Ragweed is a wind pollinated species and, like all plants that rely on wind as a means of pollen dispersal, it produces copious amounts of pollen in the hopes that some of it will eventually make it to a female ragweed flower. Unfortunately, a lot of it makes it into your eyes and nose resulting in those annoying allergies!
The ragweed flower is built for wind pollination. There are no showy flowers. Instead, the spikes of male flowers that form at the tips of the stems lack petals so that nothing gets in the way of the blowing pollen grains – billions of pollen grains! They billow unimpeded from the flowers into the air where they can remain for several days riding on air currents and traveling long distances!
Goldenrod on the other hand is insect pollinated and doesn’t produce the great quantities of pollen that ragweed does. And, goldenrod pollen is relatively large and too heavy to travel very far on the wind, so unless you stick your nose in a flower and inhale the pollen, it is unlikely to cause hay fever.
The goldenrods have showy flowers built to attract the insects that pollinate them. Insect pollination is a much more efficient way for plants to get their pollen where it needs to go – to another flower. But this efficiency does come with a cost – after all, you have to pay the “delivery man”! Plants that rely on insect pollinators usually produce sweet treats of nectar and/or protein-packed pollen as a reward for visits to their flowers.
In their travels collecting these “treats”, the insects transfer some of the pollen to other flowers resulting in pollination. The plants have to spend extra energy to produce the nectar and higher protein pollen but it pays off in the end because they get successful pollination with the production of much less pollen.
So when your allergies are really bothering you this fall, DON’T blame the goldenrod!
Until next time – Happy Gardening!