Pollen accumulates on Lake Tahoe in Sand Harbor.
The unforgivable yellow-green dust coats everything it touches. In some well-timed photos, it looks like a smoky film coating hillsides; others show clumps of the sticky stuff coating cars and sections of the lake.
It’s pollen season, and it’s hard to believe the plants don’t have a personal vendetta against anyone and everyone in the Tahoe Basin.
Although an annual ritual in late spring and early summer, the pollen count has been exceedingly high in recent days, with South Lake Tahoe’s pollen count climbing up to 133 parts per million, according to The Weather Channel allergy tracker.
For perspective, Reno has some of the highest pollen concentration in the country compared to other U.S. cities at about 90 ppm. However, Reno is more highly concentrated with grass pollen, so it isn’t visible in the same way pine pollen is around Lake Tahoe.
Pollen is expected to remain at high levels for at least a week and those with allergies are likely to experience some flare-ups.
And though the Cheeto-like dust may have defaced your car in the last few weeks, understanding how it got there might encourage you to lend some sympathy to a few neighboring pines.
Where does the pollen come from?
When it comes to pollen production, pine trees are the rabbits of the plant world, and the mountains make for the perfect breeding ground. Some pines can produce up to 5 pounds of pollen in two to four weeks.
When a pine tree reaches the ripe age of reproduction, it produces male and female pinecones. Male pinecones are the pollen carriers, and usually sit on the lower branches of the tree so they don’t pollinate the female pinecones on the same tree. Despite being evergreen, pines only produce male cones in warmer months, thus the “pollen Armageddon” of spring and summer, according to research published in American Scientist.
If a drifting grain of pollen is lucky enough to make it to a female pinecone to fertilize, it can take years to produce a seed. Animals like squirrels help distribute the seeds, which may eventually grow into trees.
But unfortunately for Jeffery pines looking for love, the vast majority of pollen won’t reach another tree; but how they end up on your car is impressive nonetheless. Evolution equipped grains of pine pollen with wing-like air cells so they can float through the air and travel farther distances, which creates more genetic variation among trees. A few lucky grains of pollen can travel hundreds of miles.
What about allergies?
The good news is most people aren’t allergic to pine pollen, and most of the allergies we experience come from grasses and other types of trees. Though nothing can be done about the concentration of pollen in the air, those with allergies can seek some relief. Allergies relating to pollen are expected to be most intense in June and July, though the pollen season extends into the fall.
Dr. Ronald Roth is an otolaryngologist at Barton Health Center in South Lake Tahoe, and said allergy drugs like Claritin, Zyrtec and Flonase can do wonders, and washing one’s hair before bed to remove traces of pollen can also help.
“(It’s) probably not the best week to sweep the driveway or use your weed whacker. Closing windows at home especially on windy days is a reasonable idea,” Roth wrote in an email to the Tribune.
Pollen can make its way inside.
“Pollen-like dust can affect indoor air quality especially if you have your windows open. Cleaning air conditioning ducts professionally before you turn on the AC each season can reduce dust pollen and indoor air contaminants,” Roth stated.
The length and intensity of pollen season’s peak depends greatly on temperature and the frequency of warm days. In Tahoe, it also is dependent on winter and spring snowfall. More snowfall contributes to plant growth come late spring and early summer, which means more pollen.
El Niño is linked to increased levels of pollen due to the vegetation growth following an intense winter. La Niña generally causes drier-than-normal winters in Lake Tahoe, but this isn’t always the case, as with the monster snowfall in 2016-17, which was followed by a fierce pollen invasion.
Research from the American Academy of Allergy Asthma and Immunology shows allergy season may even be lengthening due to the warmer temperature brought on by climate change. For now, the Tahoe Basin can expect high concentrations of pollen for at least the next few weeks.