A number of plants are associated with triggering asthma and hay fever symptoms in some people.
As a general rule, wind-pollinated plants tend to be more problematic than plants pollinated by insects or birds, as their lighter, smaller pollen is more likely to become airborne and get inhaled.
Deciduous plants which release pollen from insignificant-looking flowers are in this category.
Commonly found “problem plants” in New Zealand include:
Plants | Flowering Period | ||
Pines | Widespread source of pollen | Jul-Sep | |
Oaks | Produce a lot of pollen, some people very sensitive | Aug-Oct | |
Wattles | Produce large quantities of pollen, most settles near the plants | Aug-Nov | |
Birches | Produce lots of pollen, some people very sensitive | Oct-Nov | |
Grasses | Widespread; lots of pollen, carried by the wind | Oct-Feb | |
Plantains | Widespread; moderate pollen producers but the pollen is strongly allergenic | Oct-Feb | |
Privets | Produce lots of pollen, most of it settling on the ground within about 15m. Privet perfume an irritant for some people | Oct-Mar |
Olive trees have also recently been identified as an increasing problem as they become more widely grown here.
Other shrubs and trees which are fairly common and can trigger symptoms in some people include alder, ash, coprosma, cypress, elm, liquidambar, maple, mulberry and plane trees.
Flowers in the Asteraceae family can also be a trigger – these include daisies, marigolds, and chrysanthemums.
Flowers in the Asteraceae family can also be a trigger – these include daisies, marigolds, and chrysanthemums.
Bird and insect-pollinated plants with large, flamboyant flowers are less likely to trouble people with asthma and allergies.
However, bear in mind that strongly scented plants can affect some people.
For individuals who are affected, the best solution is avoidance:
