Are you allergic to pollen?

Because pollination times vary with the plant variety and its location, in Australia we can suffer from an extended "hayfever" season. Many trees pollinate in late winter and early spring, whilst grasses flower in spring through summer, and there are weeds, such as 'Plantain' that have very extended flowering periods, over several months. Grass pollen numbers are also higher in inland areas, where there are no natural barriers to wind dispersal.

Pollen counts tend to be lower on the east coast. This is because the prevailing winds come from the sea and there is some protection from westerly winds by the Great Dividing Range. Pollen numbers are higher on the Victorian south coast because the prevailing winds (coming from the north) carry pollen from the northerly grasslands. In South Australia and Western Australia, the concentration of pollen varies according to the prevailing winds.

Most of the grasses and plants growing in the northern coastal areas are subtropical and mainly flower in January, February and March. Allergenic grasses in the southern part of Australia are mostly Northern hemisphere grasses, with the main flowering period in October - December.
White Cypress (Murray) Pine is the only Australian tree that produces highly allergenic pollen. Its growth extends from the western slopes and plains of Eastern Australia across to Western Australia, south of the Tropic of Capricorn and it flowers from late July through to the end of August.

Wattle is frequently blamed for early spring symptoms but allergy tests (skin prick tests) seldom confirm that Wattle is the true culprit. There are, however, many species of Casuarina or Australian Oak trees, which produce pollen throughout the year and may cause hayfever symptoms at any time of the year.

Acknowledgements:
Bass DJ. The low-allergen garden. Modern Medicine1995; 38 (9):64
Ragg M. The Low Allergy Garden. Hodder & Stoughton 1996