Spring is the time plants come out of their winter hibernation and start pollinating in order to reproduce. This is important for their survival, as well as ours.
Plants relying on insects or birds for cross-pollination tend to have brightly-coloured or scented flowers. These attract bees, beetles, moths, butterflies or birds, to travel from flower to flower to get food. In the process they transfer pollen to each flower they visit. Most flowering plants and staple crop plants rely on insects or birds for successful pollination.
The other main way plants are cross-pollinated is by wind. Pollen is picked up by the wind from one plant and blows onto another. So that wind can transport pollen, plants often have pollen grains that are small and light weight. This is more common in plants that have large populations across wide areas, because it increases the chance of pollen landing on a flower on a plant of the same species. Plants that are pollinated by wind do not need to attract insects or birds so are usually dull coloured, unscented, and with small or no petals since no insect needs to land on them.
How pollen causes hay-fever
For most people with a pollen allergy, preventative medication, such as nasal cortico-steroid sprays and oral histamines, can reduce and control symptoms. It is recommended seeing your doctor for the right treatment for you. Make sure you are shown how to use the nasal sprays particularly, and if possible, start these a few weeks before the start of spring to give them time to take effect. For long-term treatment, it is recommended seeing a specialist for advice on whether allergen immunotherapy is suitable for you.
In addition to medication, you can also try to reduce your exposure to pollen. First, it is important to know the highest levels are generally in the early morning, when plants release their pollen grains, and on dry, windy days when a lot of pollen will be blowing in the air. Even if you are living in an urban area, don’t discount grass pollen as the culprit – it has been known to blow over 1,000 kilometres!
Thunderstorms in spring and summer can also be a high-risk time for people with grass pollen allergy. Although rare, a combination of high grass pollen levels and a particular type of thunderstorm can result in tiny pollen particles which, when breathed in, get deep into the airways and can trigger severe asthma symptoms.
Tips for reducing pollen exposure in spring and summer:
For more information, see the Allergy New Zealand Pollen Calendar here
Penny Jorgensen, Allergy Advisor, Allergy New Zealand.