Pollen and Plants

A number of plants are associated with triggering asthma and hay fever symptoms in some people.

As a 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.

Commonly found “problem plants” in New Zealand include:


Flowering Period


Widespread source of pollen



Produce a lot of pollen, some people very sensitive



Produce large quantities of pollen, most settles near the plants



Produce lots of pollen, some people very sensitive



Widespread; lots of pollen, carried by the wind



Widespread; moderate pollen producers but the pollen is strongly allergenic



Produce lots of pollen, most of it settling on the ground within about 15m. Privet perfume is an irritant for some people


Olive trees have also recently been identified as an increasing problem as they become more widely grown here.

Other shrubs and trees which 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.

Strongly scented plants can also affect some people.

For individuals who are affected, the best solution is avoidance:

  • Remove any plants that trouble you from your garden.
  • Try to avoid going out on windy days.
  • Keep windows closed, particularly when out in the car. Some vehicles have air intake filters fitted, which help reduce the amount of pollen taken into the car.
  • Use your asthma action plan to help you adjust your medications as your asthma gets worse/better.
  • For hay fever symptoms, talk to your healthcare practitioner or pharmacist about using a corticosteroid nose spray (eg: Flixonase® Nasal Spray) regularly during exposure, or taking an oral antihistamine tablet or liquid when needed.
  • Use pollen forecasts to help you gauge the likely risk of exposure to your triggers. MetService includes pollen levels in their forecasts – www.metservice.co.nz
  • Try to find out more about your allergic triggers with a skin prick test (you can ask your healthcare practitioner to refer you for this test).
  • Mowing, weeding and hedge-trimming can stir up pollen, dust and spores which are then inhaled at close quarters. If you are sensitive to any of these, organise someone to do these tasks for you and stay inside while it’s done. If you have to perform these tasks yourself, wear a mask to reduce exposure.
  • If mould is a trigger for your asthma, avoid organic mulches such as tree bark and manures, and use gravel mulch instead. As composting depends on moulds as well as bacteria, have someone else manage your compost. Exercise caution with potting mix – open bags slowly, and away from the face.