It’s flying season in the great outdoors.  The elm seeds continue their migration south into my driveway.  Last holiday Monday we were on our deck with some friends and suddenly enormous snowflakes were drifting lazily through the air; cottonwood seeds from the large trees across the highway.  And I can see the pollen collected along the beach at Sunoka Park and caked onto my patio furniture and vehicle.  I can also see and hear its effects on my son, who suffers from seasonal allergies.
There are the obvious culprits at work when pollen season arrives.  Maples, cedar, juniper, turf grasses, ragweed and pigweed are just a few of the better-known offenders.  Anyone who has watched a cedar hedge move about during a windy afternoon will be able to see the clouds of pollen moving into the air.  Norway and red maples flower profusely during April; all those tiny flowers contain pollen.  When bluegrass in the lawn gets a bit long and forms seed heads pollen moves up into the air each time you cut it.
Pollen sources abound but there’s another reason why there is so much of it in the spring;  botanical sexism.  A large majority of trees in our gardens, in city parks and along streets are male.  Female trees are messy.  They produce nuts, seeds and fruit that people don’t like to sweep off sidewalks and driveways.   So plant breeders and growers have focused on producing male trees which don’t produce seeds.  But they do produce pollen, lots of pollen.
In fact the average male tree produces pollen equal to the weight of a female tree’s seeds.  You won’t find any female trees in the nursery trade because any female trees that produce anything “messy” have been out of production for many years.
Gingko trees are dioecious, meaning trees are either male or female.  The females produce fruit (technically a seed) that smells like vomit when they ripen.  So, there are no female trees in the nursery trade.   Fraxinus trees are also dioecious but the female trees are prodigious when it comes to seed production; no females in the trade.  These are just two of many examples.  Growers have even figured out how to produce “all-male” versions of trees that naturally have male and female branches.
So the situation is unlikely to change, especially in urban settings.  In rural or natural areas the situation is more balanced because trees are allowed to reproduce without interference.  In large cities, however, the vast majority of trees which are planted are male.
I feel for those of you who are dealing with stuffy noses and watery eyes during pollen season.  I’m sure you are happy to see showery days like we had this past weekend if only because it keeps the pollen from flying around.  Go ahead, blame the males; the male trees, for part of the problem.

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