-Marta Robertson has been plagued by seasonal allergies since she was a teenager, and is sometimes consumed by sneezing fits that last for a minute or two at a time.
"When it's at its worst, it's itchy eyes, swollen eyes, of course, from rubbing them, nasal congestion like you wouldn't believe, tightness in the chest, that kind of stuff," says Robertson, 37, who lives in Port Coquitlam, B.C., with her husband and two children.
Although the timing can vary by location, this is a season when many Canadians have firsthand knowledge of the sort of misery Robertson goes through.
Dr. Charles Frankish, an Ottawa allergist and president of the Canadian Society of Allergy and Clinical Immunology, says about 15 to 20 per cent of people may have seasonal allergies.
"We receive way more phone calls this time of year," he notes.
"Somebody can be to the point that they're missing work, missing school, just can't sleep at night. These are the extremely severe ones."
And for those who enjoy being in the garden, like Robertson, it could mean spending less time outdoors and a period of reflection about the plant species that surround them.
"I find that there are times when I'm in there weeding or whatever that I do not stay out for as long as I would like, once the dust gets kicked up, once the pollen is out and about, you can't stay out for very long," she says.
Thomas Leo Ogren, the California-based author of "Allergy-Free Gardening," says the plants that grow nearby do have an impact on allergic individuals.
He recently did a landscape consulting job near San Francisco for a woman - pregnant and the mother of a small child - whose allergies were so bad she could hardly leave the house.
Her backyard was ringed with very large Italian cypress trees.
"When I walked up to them and just tapped them with my finger, just a real flick of my finger, a cloud of pollen just came off of them, they were just covered with pollen. And the very first thing I recommended on that job was that they call in some tree cutters, and cut all these down."
It led to a "vast improvement" in her health, says Ogren, who designed a pollen-free landscape for the American Lung Association headquarters in Richmond, Va. In particular, he's aware of which plants are dioecious - having either male or female reproductive systems. The males produce pollen and females don't.
His Ogren Plant Allergy Scale (OPALS), a rating from one to 10, is used by the United States Department of Agriculture, with one being best for allergies and 10 being the worst.
Ogren also advised another California couple: the woman had asthma, and her husband had bad hay fever.
"And right outside of his office was a big large male juniper bush and hanging over their patio was a tree that was highly allergenic and so ... I pretty much decimated the whole landscape, or at least two-thirds of it and then started over from there," said Ogren, who has also written the book "Safe Sex in the Garden."
"In this case, the lady stopped having asthma, and the man told me - he was 60-something at the time - it was the first time in decades that he wasn't taking antihistimines every day."
"In that case, we basically replaced everything male with female."
He cautions that it's not always possible to end up with such a dramatic difference, but at least some improvements can be made.
Robertson, for instance, is taking into account this year for the first time which plants are high pollen producers.
"I found out my favourite flowers, pansies, have a low pollen count, which are seasonal allergy friendly. So I'm going to go nuts with them," she says.
The pansy falls in the 1-2 range on the Ogren scale.
Frankish says people with hay fever often see flowering plants and mistakenly believe that's what is bothering them.
"Any of the flowers that are colourful and scented, they're pollinated by insects and are quite big and sticky pollen grains, and therefore they don't float through the air and so they rarely cause allergies," he said, although he notes that the smell of some flowers - lilies, for instance - can be a problem for some folks.
Ogren concurs.
"Most of the annuals are relatively benign," he says.
"The real exception is if you use a bunch of annual cut flowers and you bring them into the house where you have a drier environment. But out in the garden, most annuals, 90 per cent of them, are fine."
Ragweed, of course, is nasty from mid-August until first frost. And certain trees can be serious pollen producers, Ogren says, including maple, ash, poplars and willows.
But female varieties are available for red, silver and other maples, and they don't produce pollen.
"It's a gorgeous tree, and the only drawback is you get seeds," Ogren says.
Frankish notes that evergreen trees are better than deciduous for people with allergies, although some people can develop rashes from contact with cedar and pine resin.
The first step in garden redesign is to figure out what's there. If you don't recognize plants, take cuttings to a reputable nursery for identification, then have scratch tests done on yourself by an allergist to determine what plants are a problem for you.
Consult the literature to figure out what plants are bad for those with allergies, Ogren advises.
"The very most important thing would be to eliminate the worst stuff first," he says.
"If you can avoid whatever it is that's making you sick, then you're ahead of the game right away. You don't need any drugs."
Frankish advises allergic individuals to go for walks in the evening because that's when pollens are at their lowest level. Those allergic to grass might want to be outdoors before 7:30 a.m. or so, when many grasses begin to pollinate.
"When it's raining the pollens get washed away," he says. "A rainy day is good because it washes the pollen away... dry windy days are the worst because that increases the number of pollens in the air."
Collect your grass clippings because moulds can grow if they're left lying on the lawn. Compost and piles of dead leaves can also be a source of mould spores.
Robertson, for one, isn't about to let allergies spoil her favourite time of year. She copes by using a prescription nasal spray.
"Summer, I love it," she declares. "Pollen be damned, I still love it."
Here are some plants that are in the one to two range on the trademarked Ogren Plant Allergy Scale (OPALS) of one to 10, meaning they are best for those with seasonal allergies:
-Sweet pea
-Black-eyed Susan
-Coleus
-Foxglove
-Impatiens
-Forget-me-not
-Petunia
-Snowdrops
-Cyclamen
-Gladiolus
-Day lily
-Hosta
-Peony
-Chinese lantern
-Poppy
