Plants that are fertilized by wind-borne pollens can cause allergy symptoms because of the enormous amounts present in the air. Insects pollinate most other flowers, and they aren’t a problem. In Southwestern Ontario:
- Trees pollinate in April and May
- Grasses pollinate in late May and June
- Ragweed pollinates from mid-August until frost
It is impossible to completely avoid pollens. A vacation away from high-exposure areas during the peak of the pollen season might help. The best way to avoid pollens (and outdoor moulds) is to keep the windows closed to keep the pollen out. Use air conditioning, which cleans, cools and dries the air. Pollen counts are often highest in early morning - about 5:00–10:00 am. If you open the windows for even a short time, the pollen gets into the house and increases your allergies. It also makes it difficult to control the indoor humidity. Window air-conditioners in the bedroom are less effective, but can be helpful because you can at least keep the bedroom windows closed at night. Car air-conditioning lets you keep your car windows closed when travelling.
Pollen and mould counts
Knowing how high the pollen was yesterday is useful as a way of identifying what has been bothering you, although it’s not very good at predicting what the counts will be tomorrow. For a link to the counts from London, visit the American Academy of Allergy, Asthma & Immunology Site. Canada is included under “Pollen Count Regions.”