And the blame, more often than not, lays with home gardeners.

The researchers behind the project hope the data, which will be fed into a series of maps covering different areas of Canberra, will be able to help people understand what plants might be causing their allergic reactions and help the ACT government make smarter decisions about which trees to plant in the city's suburbs.

Dr Simon Connor, a research fellow at the school of culture, history and language within the Australian National University's College of Asia and the Pacific, said the ACT government should consider the allergy impacts of trees it plants as part of the urban forestry strategy, which was currently being finalised.

In a submission to the draft strategy, Dr Connor said tree pollen allergy rates could be reduced if low-allergen tree species were prioritised in new and replacement plantings.

The pollen mapping project will also give the public a chance to see how pollen affects their environment.

"The ultimate aim is to provide these maps to the public so people can make informed decisions about where they live, where they travel and so on," Dr Connor said.

"But also to help bridge the gap between information that the medical profession has and information that the public authorities who are responsible for urban trees have. At the moment it doesn't seem that the information the allergists are producing has filtered through to the people who choose our trees in urban areas."

Pollen is incredibly robust and Dr Connor and his colleagues usually measure how pollen is trapped through the environment to research changing climates and vegetation. Pollen traces can reveal a lot about an area's ecosystem through time.

Though it is pollen's annual health impact which is felt most severely. The financial impact of allergies in Australia was estimated 13 years ago by Access Economics to be $7.8 billion annually.

Dr Connor said he was complaining about his hay fever symptoms in Canberra when his colleague Dr Feli Hopf suggested mapping the sources of the pollen.

A measuring station at the Australian National University's Acton campus has tracked the daily pollen count since 2007, but this gives no indication of where the pollen has come from and in which areas it is most concentrated.

While the ACT government had information on what kind of street trees are located through the city, that left plenty of blank space on a Canberra pollen map.

Dr Connor started surveying home gardens to build a far more useful map of the allergenic plants in the city. He found there was at least one potentially allergenic tree for every garden in the city.

"I was just walking around looking in people's front gardens. I didn't look in their back gardens, I promise. That's actually turned out to be the critical thing, in terms of allergenic species, it's home gardeners that are largely responsible for the real problem species in Canberra," he said.

"As much as the ACT government might want to do the right thing in terms of reducing the allergy load, they've actually got to get home gardeners on board as well."

Dr Connor said the number of cypress trees, which could produce large amounts of pollen which gets picked up by the wind and spread widely, came as a surprise.

"They are one of those trees you know are around but when you actually add up how many there are, it's enormous. It's basically - every other house has got a cypress of some kind in it," he said.

"But that's often very concentrated and that's, I suppose, the surprising thing: that you'll go down a whole street where most gardens have almost no allergenic trees and then there'll be one or two gardens that will just hit the jackpot. They'll have all kinds of nasties lurking in there."

The survey, which was conducted over several months, assessed 4135 gardens and identified 4469 potentially allergenic trees. Cypress, birch and elm trees are the city's worst offenders, with many found in the inner-city leafy suburbs.

The survey found Turner had the highest concentration of allergenic trees, followed by Deakin, Red Hill, Forrest and Aranda. The suburb with the lowest concentration was Throsby, one of the city's newest, followed by Taylor, Denman Prospect and Moncrieff.

This does not mean the early residents in Canberra were suffering during the pollen seasons through the city's early years as the suburbs took shape and trees were planted.

Dr Connor said the contemporary rise of domestic cleanliness had contributed to an increase in allergies, with people more susceptible to the negative effects of pollen when now their exposure to air pollution was far lower.

Just as cypress did not cause widespread allergic reactions when many of the trees were planted in Canberra, it is hard to say which trees might cause problems in the future.

Dr Connor said the best option to future-proof the city was to make sure Canberra's urban tree canopy was as diverse as possible in order to break up any existing allergenic hot spots and to make sure no new hotspots emerged as people's allergic reactions to different plant species changed over time.

He said many suburbs currently had a low level of species diversity, which needed to change as trees were replaced and new plantings put in.

"The key thing is having a diversity of different species so that we're not kind of putting all our eggs in one basket. That also applies to looking at the future with the various climate change scenarios. If we have a diversity of different things, it's more likely that some of those are going to survive whereas if we've only got one or two species and they don't adapt well then we're in trouble," Dr Connor said.

Asthma Australia chief executive Michelle Goldman said changes to the environment which could lessen the impact asthma and allergy sufferers had on the health system were always worthy of consideration.

"Pollen is a common trigger for all people with asthma and allergies, and we're talking about a large number of people. One in five Australians have asthma and allergies," Ms Goldman said.

"If there's vegetation which is the cause of the problem and there's an opportunity to address that, it seems like a no-brainer.

"If the ACT government has the ambition to create more liveable cities through their forestry planning, this is definitely something that should be incorporated into the mix."

Dr Connor said removing trees for immediate replacements was not the answer. Gradual replacement programs which gave thought to different tree species' allergenic properties meant the long-term goal was achievable.

"It's really important that we do increase the urban tree canopy because it's going to help us to get through all these very hot summers. Urban trees are really the main thing that keep cities bearable through heatwaves, it's just a matter of how we pick the different trees that we plant," he said.