I don't want to be an allergy fanatic, and you probably don't want to be one, either. But the American Academy of Asthma, Allergy and Immunology (hmm, I think they could use a shorter name, too) reports that more than 35 million Americans are affected by seasonal allergies, often known as hay fever, and that number is growing. Informed gardeners, landscape designers and others in the hort world have a great opportunity to reduce this problem through the advice we give to others and the plant choices we make for our own landscapes.
But information about allergy-causing plants can be difficult to find; I've certainly never seen a plant tag with allergy information on it. In lieu of carting around a reference book each time you visit a nursery, here are a few ideas to point you toward low-allergy plants.
Some trees - like this maple - produce huge amounts of pollen.
1. Focus on Trees. A large tree that merits a poor allergy rating (10 is the worst on the OPALS scale) will produce much more pollen than a perennial with the same rating. In addition, if you find that a perennial is aggravating your allergies, you can easily pull it out. You might not have the resources to do the same with a mature tree. Choosing to plant trees that cause little or no allergy will make the biggest impact on the pollen problem. If you spend only one hour studying plant allergies, spend it researching the trees you are considering for your landscape.
2. Be a Feminist. Turn your mind back to high school biology, when we learned that some plants have only female parts, some have male parts, and some have both. Plants with just female parts do not produce pollen to cause allergy, while their male counterparts produce large amounts. Male plants (especially trees) are popular choices because they do not produce messy fruits, but they often have horrible allergy ratings. Be cautious about planting 'fruitless' male trees or shrubs.
Showy flowers generally don't produce much pollen.
3. Double Your Delight. Here's some good news for flower-lovers: plants that produce small amounts of sticky pollen must attract insect or bird pollinators with their brightly colored, showy flowers. That means the plants with the most beautiful flowers often cause little allergy. When some of the pollen-producing anthers have morphed into extra petals, producing a 'double' flower, the flower produces even less pollen.
4. Be Spooked by Ghostly Flowers. The flowers of wind-pollinated plants are usually small and pale green or white (hence the ghost reference). They're often so inconspicuous that you may not even realize the plant has flowers. These plants produce large amounts of lightweight, dry pollen that is carried long distances by the wind until it alights on a moist surface like a plant stigma or a human's nasal membranes.
Trumpet-shaped flowers like Vinca are good low-allergy choices.
5. Turn to Trumpets. Flowers that are shaped like trumpets generally hold their pollen inside where it won't make you sneeze. Choosing plants with trumpet-shaped flowers will be good for your nose, and bees and hummingbirds will applaud your choice as well.
Sorting out low-allergy plants from high-allergy plants is not a simple task, but hopefully these five suggestions will be a helpful way for you to make plant selections that have a positive impact on the pollen allergy problem.