St. John's, Newfoundland
Due to extreme variations in the weather and the amount of rain at this site, the tree pollen season fluctuates significantly from year to year. The pollen seasons for some trees can occur in two to three days. We try to cover the time when each can occur.
Acer sp.- The maple season has a short season with only low counts which occurs for the last week of April to early May. The main season starts from the third week of May to the third week of June and ends third week of June to the first week of July. The season can be sporadic due to the effect of weather. Some years moderate counts are possible. Certain species are known to cause allergic reactions.
Alnus sp.- The alder have a very short early season from late March to early April. The majority of the season occurs from early May to late June. The season is highly affected by weather and can be sporadic at times. The alder can cause allergic reactions in sensitized individuals.
Betula sp.- The birch pollen season can vary from year to year. Low to high counts can be observed and are often sporadic. The season can start from the third week of april to the third week of may and end late may to late june.
Larix sp.- The larch and tamaracks produce low to moderate counts, depending on the year, and the pollen season varies a great deal from year to year due to cyclical patterns and the effect of weather. The season can start from the first to the third week of May and end the third week of May to early June. They have been associated with allergic reactions.
Pinaceae family- The season for the pine, spruce and firs can vary both in pollen counts and when the pollen season occurs. Counts fluctuate a great deal throughout the season from low to high levels. The season can start mid-May in warm years like 201 and 2012. Generally the season starts early June and ends late June to mid-July. They are of significance in causing allergic reactions in individuals who are sensitized.
Cupressaceae family- The cedars, junipers and yews' produce low to moderate counts, with high counts possible some years. A short early season can occur around late March to early April. The main season can start the second to last week of April and end the second week of June to early July. Most species in Canada are not known to cause allergic reactions.
Populus sp.- The pollen season for poplar and aspen can vary drastically from year to year. The season can start form early to late April and end mid-May to early June. There are usually just a few days where relevant counts are observed at this collection site. This has to do with the great fluctuations in temperature and the abundance of rain during the season. They may not cause allergic reactions at these levels.
Fagus sp.- The beech season can vary a great deal from year to year due to cyclical patterns and the effect of weather. Low counts to high counts are observed depending on the year. The season can start late the third week of May to the first week of June and end the second to the last week of June. The amount of pollen captured is also dependant on where the sampler is located.
Quercus sp.- The oak season is highly affected by weather. The season can start from early May to late June and end the third week of June to mid-July. Some years only low counts are observed but other years moderate counts are obtained. Some species can cause reactions.
Ulmus sp.- The elms can be important allergens. The season can be sporadic which is mostly due to the effect of weather. Some years moderate counts are observed but most years only low counts are captured. The season can start the third week of April to the third week of May and end the second to the last week of May.
Rumex sp.- Sorrel or Dock - The season can start late May to the third week of June and end mid-August. Mostly low, with the occasional moderate, counts are observed.
Ambrosia sp.- Ragweed counts are always low and very sporadic. Season can start early August and end mid-October.
Gramineae family- The grass season can start mid-May to mid-June and end late September to mid-October. The highest counts are observed from the second week of June to early August.
Compositae family- A group of weeds which are similar microscopically and can be wind or insect pollinated. Some of the weeds in this group can cause allergic reactions and moderate counts are observed in June.
Plantago sp.- The plantains produce low counts. The season can start from the third week of June to the second week of July and end mid to late September. May cause allergic reactions in individuals who are highly sensitized.
Urticaceae sp.- The counts for the nettles are always low but they are important allergens due to their small size. The season can start from mid-June to early July and end early to mid-September.
Diatrypaceae sp.- Very sporadic counts are observed throughout all of our collecting season, and the highest numbers are found in cool wet weather. Clinical significance in unknown.
Leptosphaeria sp. & Leptosphaeria look-alikes- These two are grouped together since they are in the same class of fungi and are similar microscopically. The season is May to mid-October with great fluctuations in counts from day to day which is probably due to the effect of weather.
Erysiphe (Oospora) sp.- Powdery mildew - The season is from May to mid-October.
Boletus sp.- Spore counts for this mushroom can reach very high numbers from the end of July well into October. Can be a significant allergen.
Coprinus sp.- The majority of the season is from July to well into October. Considered an important allergen.
Ganoderma sp.- This fungus can produce very high spore numbers and the majority of the season is from mid-June to mid-October. Can be a significant allergen.
Uredinales sp.- The season with significant counts is from mid-June to mid-October. Allergenicity at these levels is not well understood.
Ustilaginales sp.- High counts occur from June to mid-October. Allergenicity at these levels is not well understood.)
Penicillium sp. & Aspergillus sp.- These two genera can occur throughout our counting season from March to the end of October. Highest counts are from August to early October. They are considered important allergens.
Cladosporium sp.- Very high numbers are recorded. Occurs throughout the year with significant counts occuring from March to well into October. The highest counts occur from June to mid-October.
Fusarium sp.- Counts fluctuate a lot throughout the counting season which is normal for this fungus. Majority of the season is June to mid-October.
Helicomyces sp.- Very high counts are observed. Most of the season is from May to early October. Medical significance is unknown.
Botrytis sp.- This fungal spore is considered to be a significant allergen. Season is from early June to early October.
Pithomyces sp.- Moderate counts are observed from August to the end of September. Medical significance is unknown.
Polythrincium sp.- Moderate counts are observed from late July to early October. Medical significance is unknown.
Epicoccum sp.- Moderate counts are observed in July and August. May not play a significant role in allergies except to those individuals who are highly sensitized.
Myxomycetes- Moderate counts are observed from May to early October. Allergenicity is not well understood.
Last Updated : 4 March 2015
The information presented here is designed to inform, not replace, the relationship that exists between a patient and a medical professional.