The lightweight, miniscule, dry grains of pollen are easily carried by the wind, so if you’re one of the approximately 50 million Americans who have nasal allergies, according to the Asthma and Allergy Foundation of America (AAFA), you don’t want to be downwind of pollen. When pollen gets into your mucous membranes, it triggers an allergic reaction, says David R. Stukus, MD, a member of the AAFA’s board of directors and an associate professor in the pediatrics section of allergy/immunology at Nationwide’s Children’s Hospital in Columbus, Ohio. When you have a pollen allergy, your immune system sees pollen as a foreign invader and forms an antibody, known as IgE, to fight it, Dr. Stukus says. “When you breathe in pollen, it attaches to IgE on allergy cells that are present throughout your body but mainly within your respiratory tract," he says. “This attachment unlocks the allergy cells and causes the release of chemicals called histamines into your blood. Histamines cause the symptoms you’re all too familiar with: runny nose; sneezing; itchy eyes, ears, and mouth; and red, swollen, watery eyes.” Most of the pollen that causes allergy symptoms comes from trees, weeds, and grasses, Stukus says. Trees, which release pollen in the spring, “often cause the most severe symptoms because they’re the first exposure of the growing season after a long winter of reduced allergy symptoms,” he says. Grasses, which typically pollinate in the summer months, are the most common cause of summer respiratory allergies, he says, and ragweed is the most common cause of allergy symptoms in the late summer and fall. If you have seasonal allergies, pay attention to wind patterns when you decide where to put certain plants in your yard, particularly in relation to your bedroom windows, Stukus says. However, pollen that causes allergy symptoms is so small and light that it can be blown from miles away. “It’s often not the plants in a person’s yard that cause problems, but those from their neighbors’ or landscaping down the street,” he says.
Best Plants for Respiratory Allergies
These plants are less likely to trigger allergy symptoms:
Delphinium. A stately perennial, delphinium is often grown for its showy, spurred flowers, according to the National Gardening Association. Its peak pollen time is when it blooms in early summer. Also known as larkspur, delphinium grows well where summers are relatively cool and moist, such as the Pacific Northwest and the Northeast.Daffodil. Daffodils, which tolerate the cold well, grow throughout the United States. They bloom in early spring and can last from six weeks to six months, depending on where you live, according to the American Daffodil Society.Purple leaf plum tree. This tree’s peak pollen season is early spring, when it blooms. It can be found in yards and gardens across the country.Evergreen trees and shrubs. There are numerous varieties of evergreen trees and shrubs, called “evergreen” because their leaves or needles remain intact year-round. Conifers, most of which are evergreens, shed pollen but only for a short time in the spring.
Worst Plants for Respiratory Allergies Certain trees can aggravate respiratory allergies. Those to avoid include:
Ash (Fraxinus). Ash trees produce large amounts of pollen, according to the Asthma Society of Ireland. Ash can be found throughout North America, although the species has been dying out because of invasive insects.Birch (Betula). Birch trees, which are found in almost every state, release pollen in the spring, when they flower.Oak (Quercus). Oak trees can be found worldwide, and there are more than 80 species of oak trees in North America. They flower in the spring and develop over the summer. The pollen that triggers your allergy symptoms develops the following spring. If you have oak trees in your yard and want to remove them, your local garden center or nursery should be able to help you identify which trees are male and which are the less-pollen-producing female trees.
Shrubs, like trees, can be male or female, and people with respiratory allergies should steer clear of male shrubs, which produce more pollen, according to the Asthma Society of Ireland. In general, shrubs to avoid include:
Forsythia. This is one of the first shrubs to bloom at the end of winter, as spring is just beginning. This is its peak pollen-releasing time, according to the Arbor Day Foundation. Forsythia grows well everywhere except Florida, southern Texas, California, and the northern climates of Montana, Minnesota, and North Dakota.Holly. Holly shrubs bloom in the spring. They’re found throughout the United States, although the tree version, which can grow up to 40 feet tall, is most common in southern states.
When it comes to grasses, there’s one prime offender:
Zoysia grass. Although it’s popular for being drought-tolerant and sun-loving, zoysia grass is among the worst pollen offenders, according to the Missouri Botanical Garden. Zoysia grass is grown from the northern Atlantic states to Florida and from the Gulf Coast to Texas. The growing season is from early spring to late fall. Keep this grass cut short to limit blooming and pollen production.
Allergy testing is the best way to determine which plants trigger your allergic reactions, according to the American Academy of Allergy, Asthma & Immunology. Your allergist can also help you find ways to avoid troublesome plants and manage your allergy symptoms.
