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Garden Talk
Pollen Season
By Katherine Hale
Marketing & Communications Assistant
Ah, spring, a time of awakening and renewal, of warmer and longer days filled with bird songs, of cherry blossoms and tulips—not to mention drifts of yellow pollen filling the air and blanketing everything left outside for more than a few hours. Informally known as “The Pollening,” this rite of passage is an annual occurrence in central North Carolina, much to the bewilderment and chagrin of newcomers and allergy sufferers alike.
All flowering plants produce pollen in some fashion or other, but the exact quantity and method of distribution varies widely depending on the species. Those pollinated by animals—whether bats, birds, bees, flies, ants or other insects—tend to produce small quantities of relatively large and “sticky” pollen, which is delivered directly to another flower via its particular messenger. These flowers tend to be colorful and showy, shaped to attract their pollinators’ attention and provide nectar as a reward for a job well done. Plants that are animal-pollinated include the majority of horticulturally grown species and a large number of commercially grown fruits and vegetables, including blueberries, squash and cabbage.
However, there are also a large number of plants that have embraced the opposite strategy and left the fate of the next generation entirely dependent on the vagaries of the weather. Instead of pouring their energy into large attractive flowers, wind-pollinated plants produce multiple sets of small flowers that barely register as such to the human eye, which pump out huge volumes of small, lightweight pollen into the atmosphere. Instead of being guided directly to its intended destination, this pollen drifts on the breeze, with some of it hopefully landing in the right spot eventually. If animal pollination is a small and artisanal arrangement, wind pollination is a numbers game, relying on high volumes to overcome all of the odds stacked against them. Believe it or not, this has proved to be a wildly successful strategy for grasses and staple food crops like rice, wheat and maize, as well as all conifers, which evolved millions of years before the first flowers and most of their pollinators.
Here in central North Carolina, the landscape is dominated by wind-pollinated trees like pines, oaks and hickories, all of which release their pollen in predictable waves over a period of several weeks in mid- to late spring. Multiply the number of trees by the number of flowers on each plant, and it’s easy to see why the landscape is so coated with yellow every year. Climate change is also impacting pollen season, with warmer temperatures triggering the release of larger quantities of pollen earlier in the year.
Unfortunately, there’s not much to be done about pollen season except grin and bear it, bringing furniture and other items indoors if possible, wearing a mask if necessary to avoid exposure, and/or postponing outdoor activity until later in the day or early evening when daily pollen counts have declined. Frequent rains also help, taking the pollen out of the air and turning the rivers and streams a startlingly bright yellow. Eventually, this too will pass, and everyone can breathe a sigh of relief—at least until the grasses and other wind-pollinated herbaceous plants start releasing their own pollen later in the summer.
Photos, from top: Oak pollen tassels dangling from a branch in early spring, by Karen Webbink; a great blue heron (Ardea herodias) fishing by the wooden Zig-zag Bridge in the Culberson Asiatic Arboretum in spite of the large volumes of pollen coating the water's surface, by Cathi Bodine; pine pollen tassels emitting pollen, by Sue Lannon.
