It’s that time of year again when a golden haze can be seen in the air as gusts of wind blow swirling clouds of powdery pine pollen across the Estes Valley.
During pine pollen season – from about mid- to late May and continuing through June and into the first few weeks of July – blankets of gritty yellow dust settle on decks, windows, sidewalks, and cars.
If you leave your windows open, you will notice pollen on your furniture and countertops. If you walk by Lake Estes, Marys Lake, or one of the lakes in Rocky Mountain National Park, you may notice a layer of yellow pollen floating on the water’s surface or blown into a windrow along the shore.
This phenomenon is a seasonal process with ecological significance, explained Daniel Burcham, an arborist and assistant professor in the Department of Horticulture and Landscape Architecture in the College of Agricultural Sciences at Colorado State University, in an interview with the Estes Valley Voice.
Ponderosa, lodgepole, bristlecone, and other pine species, which dominate the landscape surrounding Estes Park, are anemophilous. That means they spread their pollen using wind rather than pollinating insects, said Burcham.
Pinecones are classified as either male or female. Female pinecones are hard, woody, cone-shaped structures with spiral scales that protect the pinecone’s seeds. Each woody scale has seeds tucked deep into the cone near the stem. The scales open as the cone dries out, and the seeds are released.
Male pinecones, known as pollen cones, are smaller, softer, and spongy. Pollen grains have microscopic spiky structures which help the wind carry them through the air. Depending on the pine species, when a grain of pollen lands on a female pinecone, reaching the seed can take 18 to 36 months.
To ensure fertilization, male pinecones release massive quantities of pollen, much of which is wasted. However, once fertilized, the seeds are dispersed by the wind and, if the conditions are right, a new pine tree may take root.
After the catkins release their pollen, Burcham said they turn brown and fall off the tree, a process referred to as senescence.
Pine pollen, allergies, weather, and wind
Because pine pollen grains are larger than other pollens, they do not enter the nasal cavity as easily as smaller pollen grains, which are less allergenic than many other types of pollen. This time of year, allergy symptoms are more likely to be caused by grass, weeds, and mold spores. However, pine pollen can still trigger a reaction in about two to three percent of the population.
Burcham said both the life stage of the trees and weather conditions can influence the production of pollen. Warmer temperatures, especially mild winters and a lack of late frosts, can increase pollen production. This year, the Estes Valley experienced a cool, wet spring, but as the temperatures have risen over the past two weeks, so too has the pollen count.
Curiously, a rainy spring and late frosts can reduce the amount of pollen in the air, but rain and humidity can also have a complex and sometimes contradictory impact on pine pollen levels. While a light shower can wash pollen away, a heavy rain can actually break down pollen into smaller particles and cause pollen counts to rise.
Burcham explained that warm, dry, and windy days provide optimal conditions for high pollen counts and favorable conditions for pollination.
To check for local air quality and the pollen forecast, click here.
Medicinal uses for pine pollen
Pine pollen has been used in herbal and traditional medicine for centuries as a source of carbohydrates, amino acids, vitamins, and minerals like zinc and selenium.
And because it contains testosterone, Chinese medicine has used it to boost yang energy, vitality, and stamina in men. Taoist herbalism has used the yellow powder as a longevity tonic to replenish jing or essence and promote healthy aging.
Many brick-and-mortar and online natural food stores sell pine pollen as a powder, in tinctures, and capsules, but with caveats about its efficacy.
Living with pine pollen
On breezy or dry days, keeping windows closed is a good idea. Pollen-blocking window screens can help reduce the amount of pollen that makes it indoors.
Historically, pollen was used to dye fabrics, so it is important to remember that pollen can stain fabrics. Pine pollen can also adhere to surfaces like house siding, outdoor furniture, and even cars. If left for extended periods, the pollen, which is acidic, can corrode and stain paint finishes.
There are a few dos and don’ts when cleaning up pine pollen. Use a garden hose to wash pollen off outdoor walkways and desks gently, and vacuum furniture with upholstery attachments. Using a power washer to hose down pollen on outdoor furniture, siding, or the finish on a car can abrade surfaces and even activate some of its acidic qualities. Cleaning pollen off surfaces, such as glass top tables and wood finishes, can be tricky, and if you’re not careful, the process can cause damage. One swipe of a dry cloth can result in light scratches.
Using soapy water can help encapsulate the pollen and loosen its grip while also providing enough lubricant to prevent or limit scratches, and a microfiber cloth can be a gentle way to remove the grains of pollen attached to a surface.