For people with hay fever, grass pollen is the most common trigger for symptoms. However, people with pollen allergies can also be allergic to weed, tree, or flower pollen. Within these groups, some plants may cause more symptoms than others.
Knowing which types of pollen cause symptoms can help with avoiding symptoms. Other factors, such as where a person lives, how close they are to allergenic plants, and the impact of climate change also influences symptoms.
Read on to learn more about the worst plants for people with pollen allergies, as well as a list of low allergen plants they may want to include in their home or garden.
The worst plants for a person with allergies will depend on what exactly they are allergic to. A person with a pollen allergy, or hay fever, may react to:
- grass pollen
- weed pollen
- tree pollen
People with hay fever can have just one of these allergies or multiple.
Additionally, within each category of plant, some species may be more problematic than others. The worst plants for hay fever are often:
- Deciduous: Deciduous plants shed their leaves seasonally and release pollen from their flowers.
- Wind-pollinating: This means they rely on the wind to carry their pollen. Wind-pollinating plants produce pollen that is small and light enough to become airborne, which makes it easy to inhale when the pollen count is high.
- Prolific: Some plants release more pollen than others. Plants that release high amounts of pollen are more allergenic.
A doctor can perform a test to determine what the person is allergic to. Alternatively, a person may be able to tell by noticing when their symptoms appear in the year.
Grass pollen is one of the most common hay fever triggers. Most types spread their pollen entirely via the air, and they release large amounts of it. Additionally, grass is very common, both in cities and in the country.
Many types of grass could trigger symptoms, but some of the species most likely to cause a problem include:
- Kentucky blue
- perennial rye
- salt grass
- sweet vernal
In the northern United States, grass pollen can cause problems for people with allergies in the late spring to early summer. In the southern U.S., grass pollen can cause problems at different points throughout the year.
As grasses tend to feature in gardens and public spaces, people may also be able to avoid the pollen by staying inside when pollen counts are high.
Tree pollen allergies are less common than allergies to other plants, such as grasses and weeds. For people who do have this type of allergy, symptoms begin in early spring in the U.S. Some trees can begin releasing pollen as early as February or January.
Trees that cause the most symptoms include:
- box elder
- fruitless olive
Around 15% of people in the U.S. are allergic to ragweed pollen. While a person may not consciously make the decision to grow weeds, these plants can thrive in a person’s garden unless they actively remove them.
In addition to ragweed, several other weed plants can pose a particular problem for people with allergies, including:
- burning bush
- Russian thistle
Flowers and vines that rely on wind pollination can also trigger hay fever in some people. This includes flowering plants such as:
Daisies, chrysanthemums, and sunflowers are distant relatives of ragweed. They may trigger symptoms in people with weed pollen allergies, but this may vary depending on the individual.
When choosing plants for the garden or home, people with hay fever can opt for low allergen plants to reduce symptoms.
The United Kingdom charity Allergy UK recommends that people with pollen allergies choose flowering plants that rely on insects or birds for pollination. These plants tend to have large trumpet or bell-shaped flowers that attract pollinators. They may be very colorful or have multiple flowers on one stem.
Some options include:
- dusty miller
- dahlia (formal-double)
- bird of paradise
- rose (unscented, tea-type)
The Royal College of Pathologists in the U.K. produced a leaflet on low allergen gardens, which also recommends:
- bleeding heart
- common poppy
- lady’s mantle
- larkspur (delphinium)
- love-in-a-mist (nigella)
- masterworts (astrantia)
- sea holly
- star jasmine
Some types of grass that may be better options for people with grass pollen allergy include:
- Calamagrostis x acutiflora “Karl Foerster”
- St. Augustine
- female cultivars of buffalo grass, such as “Legacy” or “UC Verde”
- male-sterile hybrid Bermuda grasses
Trees and shrubs
Some low allergen trees and shrubs include:
- apple tree
- boxwood, kept pruned
- chaste tree
- cherry laurel
- Chinese fan palm
- confetti bush
- English holly, female
- English yew, female
- fern pine, female
- hardy rubber tree
- Mexican orange blossom
- pear tree
- plum tree
- red maple, female
- tea plant
- wax myrtle, female
Wind-pollinating plants are often the worst plants for pollen allergies. The pollen from these plants is small and lightweight, which makes it easy to inhale. People can minimize their exposure by opting for low allergen alternatives in their home and garden, such as plants that rely on birds or insects for pollination.
Not everyone with hay fever needs to avoid all of the plants that can potentially trigger allergies. It can help to narrow down which type of pollen allergy a person has. If a person is unsure, they can consider speaking with a doctor about allergy testing.