|Lots of male pollen catkins developing on a mature|
Pinus sylvestris (Scotch Pine) ©2013 BDG
With all of the beautiful trees and shrubs that flower each spring comes the inevitable blanket of pollen. And right now in New England we are enduring some very high levels of tree pollen. Maples, Oaks, Ash and Lindens are some of the common contributors recently, and they are the most allergenic pollens. Coming shortly is Birch pollen and that can cause some significant reactions. If you have noticed some congestion, a sore throat or been feeling lousy and lethargic it is probably the result of this early season pollen.
When we think of pollen we think about honey or bumble bees floating around our ornamental gardens and visiting our flowering shrubs and perennials, but in fact it is the bigger trees, early in the season, that provide most of the pollen that causes our allergies. Maples tend to flower just as their leaf buds are breaking, and several weeks ago you may remember the chartreuse color on the Norway Maples before their leaves broke. All trees flower, though we often don't see them since they can be inconspicuous. It is all part of the process of procreating.
Some plants can self-pollinate, others need to be pollinated by a neighboring plant and some need a different sex plant to pollinate. More on this later.
|Close-up of the Scotch Pine. ©2013 BDG|
Just as most of the allergenic trees are finishing flowering, the most prolific spreader of pollen emerges: The Pine family. Usually in early June here in New England, the Pine trees develop their male catkins that disperse pollen that covers everything and everyone in clouds of yellow pollen. This is what we think of when we talk pollen and everyone closes their windows as it can travel in visible clouds on the wind. Interestingly, Pine pollen is not as allergenic as the other tree pollens, but it appears in such quantities that it often can lead to sneezing and hard breathing because of the concentrated level of particles.
|Pinus strobus (White Pine) just developing. ©2013 BDG|
Check out this pollen forecast site if you want to know what is happening with tree pollen in your area. It also covers grass, weed and mold. The last couple of weeks have been bad, I have felt a little lethargic, had some mild headaches and breathing was just a little heavier. With the mild weather and no rain, the pollen has been prolific and a little breeze helps to carry the pollen in the air. The last couple of days, as the weather has been wet, pollen levels have dissipated, but the forecast shows pollen counts coming back late in the weekend as the weather clears.
What is pollen?
Pollen is released from male flowers or the male part of a flower and it is used to fertilize female flowers or cones.
Many plants are monoecious, meaning they have male and female parts on the same tree, while others are dioecious, meaning plants are either male or female.
|Betula populifolia (Gray Birch) single male catkins at|
the end of the branch. Pollen coming soon. ©2013 BDG
The best, and very common, example of a dioecious plant is Holly. In order to bear fruit on female hollies, it is important to have a male holly within site to provide pollen to fertilize the female flower, which will turn into the berries that we love. If you have Hollies that don't berry, it is often because there is not a pollinator nearby, or it is a male plant. Gingko is another dioecious plant, and you want to make sure that you do not get a female Gingko, as the fruit is putrid when it ripens. We had one on our college campus and in the fall it smelled like a combination of a sewer and vomit. Nurseries do try to keep them out of the trade, but on occasion they can be found.
|Dogwood flowers are in the center, the white 'petals' are |
actually not part of the flower. These flowers are 'perfect'
because they contain both male and female parts
within the same flower. ©2013 BDG
Birch, Oak and Pine are common examples of monoecious trees with both male, pollen bearing flowers or catkins and female flowers. The female ovary is what matures into catkins, nuts and cones respectively.
While we may not like the clouds of Pine pollen to come, it is believed to have very powerful positive effects, especially for men. Some research says that Pine pollen can increase male testosterone. If you are feeling a little low on energy or with that 'drive', then spend a few hours out breathing the clouds of pollen over the next few weeks.
While pollen can be a pain to clean up and in many it causes bad physical reactions, it is just plants doing their best to extend the existence of their species.