Pollen Reduction By Tree and Plant Selection.
Allergies and Selecting Trees
Have you wondered why it seem so many people today have allergies? Without a doubt, more people today than 50 years ago, the highest percentage ever, are suffering.
As an example, I know of a school that cannot have peanut butter present because a child there could suffer a life-threatening reaction if exposed. Johns Hopkins Medical Institute has confirmed that overall in America, 1.5% of the population is severely allergic to tree nuts like cashews and walnuts, especially peanuts. In children the percentage is lower, about .8%, but has actually DOUBLED in just the past decade. In the nearby school I mentioned, there is a randomly, but unfortunately, high concentration of peanut allergy sufferers.
Could our trees that we are planting also be a cause of allergies? Better yet, could there be species that help REDUCE the allergens in the air around them? If you want to save time and not read my long discourse, SKIP DOWN to the recommended list of trees to plant at the end of this article. I won't be insulted. Honest. How will i know anyway?
Certainly using trees to get some of the dust out of the air will help EVERYONE, especially to help reduce allergy sufferers including the reduction of asthma-attack triggers. For 54.3% of America, skin exposed to allergy-causing substances will positively show a reaction to at least one of the "top ten troublemakers" below:
Dust mite Common (German) cockroach Cats (fur, dander, saliva, etc.) Perennial rye (lawn grass) Short ragweed (hay fever is the result) Bermuda grass (lawn grass, putting greens) Russian thistle White oak Alternia alternata (a type of mold) Peanuts (or also, cashews, walnuts)
So what might we do when selecting trees to plant? We must first realize there have been major changes in our urban and rural tree planting over the years, such as to adjust for the loss of elm trees. In the early 1900's elms were extremely common hroughout the eastern United States. When the incurable Dutch Elm Disease killed about half their number, then following 1945 in another outbreak further reduced the number from about 76 million to under 10 million today, other species were used in their place. Maybe some of those species, in hindsight, were a mistake to plant.
How about a little bit of humorous trivia? There is no such thing as a Dutch Elm tree. There are about 30 or so understood elm species in the world. Because the disease which infected trees all across Europe since the 1800's was finally discovered to be from a fungus and its spores by scientists in Holland, the "Dutch" moniker was applied in 1917...
An elm tree like our American Elm, interestingly, the largest elm of all, makes little airborne pollen because it is mostly pollinated by insects. (All elms have both male and female flowers present on each tree, they're called "monoecious" by botanists). Therefore, elms will cause less allergy problems for people.
Unfortunately, since 1949, our USDA, through its yearbook, has recommended trees which are males because they are less "messy." No acorns and no fruit to drop on the ground and rot, but alas, these trees ALWAYS make lots of pollen. About 150 million elm trees have been replaced with pollinating male hardwood trees!
What is best recommended as suitable for urban plantings does minimize the total amount of pollen in the air. Selections should be made accordingly. Trees with high pollen production should be kept out of all dense urban area plantings, if possible. This is even more important when surrounding schools, nursing homes, and hospitals, even in a rural area. "Street trees" in downtown areas, trees near ANY home should be LOW POLLEN PRODUCERS. Trees with high pollen production should never be near fresh air ducts for ANY building, anywhere.
Municipalities should incorporate low pollen production trees into land use regulations. Lists of trees that are allowed in land use plans should reflect good health factors for our communities. Think of all the lawsuits that are derived as a result of poor planning; tree planning can be included too.
In conclusion, here's what you needed to see: BEST TREES TO PLANT FOR ALLERGY PREVENTION
Female Ash Trees Female Red Maple Trees Female Red Locust Trees Double Flowering Cherry Trees
GOOD TREES TO PLANT
Flowering Pears and Plums Pines and Spruces Dogwoods
POOR TREES, NOT TO PLANT
White Oak Trees Red Oak Trees Male Ash Trees Male Mullberry Trees Male Red Maple Male Junipers
See more articles by B Hirst at the Highland Hill Farm website http://www.seedlingsrus.com or http://www.zone5trees.com
About the author: Selection of trees and plants should be made with an eye towards reducing pollen and other allergens in the environment. Bill talks about considering trees, shrubs, and flowers BEFORE they are to be planted.
