Clouds of yellow pollen are starting to float about Otago, dusting windows, cars and even street gutters.
They were particularly visible from the air over the Taieri this week as dry settled weather sat over the area.
University of Otago botanist Associate Prof Janice Lord said pollen was microscopic, powdery grains from male plants which fertilised their female counterparts after being spread by wind, insects or birds.
"It’s basically sperm," she said.
It enabled the propagation of many plant species, including trees, grasses, and weeds.
However, pollen was also the primary cause of allergies for an estimated 1 in 5 people in New Zealand.
"It's lovely to look at the pollen clouds, but not if you've got hay fever or asthma."
She said the increasing amount of forestry around Otago was creating increasing amounts of pollen at this time of year.
"Pine is notorious at producing vast amounts of pollen.
"They use wind-pollination, which is a bit hit and miss.
"The likelihood of each pollen grain landing on the right place is pretty low, but if you send loads of it out there, there’s a greater chance it will hit the right spot.
"Given the amount of pine that's been planted around Otago, this is going to become more and more of a spring phenomenon.
"But don't blame the plants. It's not all the plants’ fault."
While it was unpleasant for those who were allergic to pollen, she said it would not last long — just until about the end of September.
Assoc Prof Lord said there were many remedies and medications available to ameliorate the symptoms of hay fever, but being mindful of which way the wind was blowing would also help.
"If you have clothing or bedding on the clothes line, and the wind is blowing towards you from some pine plantations, then don't put the washing on the line."
She also recommended keeping windows and doors closed.
"I hate to say that, but that's what I had to do with my son when it was really bad.
"It's a shame that we've got to a state where we're allergic to something that's natural."
