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Predominant Pollen and Spores

St. John's, Newfoundland

Tree pollen and spore seasons fluctuate from year to year by as much as two to four weeks at this site due to the effect of weather. The pollen and spore seasons described here are generalizations as to when pollination/sporulation occurs.

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Predominant Pollen for St. John’s, Newfoundland

Tree pollen seasons fluctuate from year to year by as much as two to four weeks at this site due to the effect of weather. The pollen seasons described here are generalizations as to when pollination occurs.

Alder (Alnus sp.)

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.

Beech (Fagus sp.)

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.

Birch (Betula sp.)

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.

Cedars, Junipers and Yew (Cupressaceae family)

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.

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.

Dock weed & Sheep sorrel weed (Rumex sp.)

The season for dock weed & sheep sorrel weed can start late May to the third week of June and end mid-August. Mostly low, with the occasional moderate, counts are observed.

Elm (Ulmus sp.)
Elm 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.
Grasses (Gramineae family)
Grasses 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.
Larch & Tamaracks (Larix sp.)

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.

Maple (Acer sp.)
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.
Nettles (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.
Oak (Quercus sp.)
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.
Pine, fir and spruce (Pinaceae family)
Pine, fir and spruce. season 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.
Plantains (Plantago sp.)
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.
Poplar, cottonwood and aspen (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.
Ragweed (Ambrosia sp.)
Ragweed counts are always low and very sporadic. Season can start early August and end mid-October.

Predominant Spores for St. John’s, Newfoundland

Spore seasons fluctuate from year to year by as much as two to four weeks at this site due to the effect of weather. Spores described here are generalizations as to when sporulation occurs.

Aspergillus sp.
Aspergillus occurs throughout our counting season from March to the end of October. Highest counts are from August to early October. They are considered important allergens.
Boletus sp.
Spore counts for Boletus mushroom can reach very high numbers from the end of July well into October. Can be a significant allergen.
Botrytis sp.
Counts for Botrytis fungal spore is considered to be a significant allergen. Season is from early June to early October.
Cladosporium sp.
Very high numbers of Cladosporium are recorded. Occurs throughout the year with significant counts occurring from March to well into October. The highest counts occur from June to mid-October.
Coprinus sp.

The majority of the coprinus season is from July to well into October. Considered an important allergen.

Diatrypaceae sp.
Very sporadic counts of Diatrypaceae are observed throughout all of our collecting season, and the highest numbers are found in cool wet weather. Clinical significance in unknown.
Epicoccum sp.
Moderate counts of epicoccum are observed in July and August. May not play a significant role in allergies except to those individuals who are highly sensitized.
Erysiphe (Oospora) sp.
Erysiphe, also known as powdery mildew, season is from May to mid-October.
Fusarium sp.
Sporadic counts of Fusarium counts fluctuate a lot throughout the counting season which is normal for this fungus. Majority of the season is June to mid-October.
Ganoderma sp.
Very high counts of Ganoderma 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.
Helicomyces sp.
Very high counts of Helicomyces are observed. Most of the season is from May to early October. Medical significance is unknown.
Leptosphaeria sp.
Leptosphaeria season is May to mid-October with great fluctuations in counts from day to day which is probably due to the effect of weather.
Myxomycetes

Moderate counts of myxomycetes are observed from May to early October. Allergenicity is not well understood.

Penicillium sp.
Penicillium occurs throughout our counting season from March to the end of October. Highest counts are from August to early October. They are considered important allergens.
Pithomyces sp.
Moderate counts of Pithomyces are observed from August to the end of September. Medical significance is unknown.
Polythrincium sp.

Moderate counts of polythrincium are observed from late July to early October. Medical significance is unknown.

Uredinales sp.
Uredinales season with significant counts is from mid-June to mid-October. Allergenicity at these levels is not well understood.
Ustilaginales sp.
High counts of Ustilaginales occur from June to mid-October. Allergenicity at these levels is not well understood.

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