). Because these plants are
wind-pollinated, they produce a lot of powdery, easily inhaled pollen that can
trigger allergic responses. Insect pollinated plants, such as flowers and
vegetables, have pollen that is large and sticky, which generally does not cause
as many problems. However, individuals who are repeatedly exposed to these
plants may develop allergies.
The most typical allergenic plants include ragweed, pigweeds, and all
grasses. Large shade trees such as oaks, elms, maples, pecans, mulberries, and
cottonwoods can also cause problems. Most individuals are allergic to only one
or two trees. Because these trees pollinate a few weeks each year, allergic
reactions can be avoided by staying indoors, wearing a protective mask, or
taking medication during the weeks that they are pollinating. Some individuals
may also be allergic to trees in the juniper, cypress, and sequoia families
(including the Eastern Red Cedar seen on many Virginia roadsides). These trees
pollinate in the wintery months of January, February, Early March.
Besides trees and grasses, mold and fungi can also cause allergic reactions.
They release spores into the atmosphere all year long in areas where there is
abundant organic matter, moisture, and warmth. Leaf piles and compost areas can
produce many molds and fungi. The results of working near a compost pile could
be even more serious than asthma or allergic rhinitis, as some fungi can
colonize in asthmatic bronchial tubes, leading to more serious conditions.
Prevention
If you experience allergic reactions while working outdoors, consult with
your local doctor or allergist to determine which plants are responsible and
when they pollinate. You can then formulate your own personalized calendar
indicating your best and worst times to be outdoors.
If you do go outside, there are several ways to minimize your exposure to
pollen. These include wearing gloves, a long sleeved shirt, hat, and sunglasses
or goggles. A pollen mask may also be necessary. After working outside, take a
shower, thoroughly wash hair, and change clothes.
Weather conditions can affect the abundance of allergens in the air. Wind
pollinated plants will not release pollen when it is raining, and instead are
more dangerous on hot, windy days. Mold and fungi spores, on the other hand, are
more abundant during wet weather. Save gardening for days when your allergen
counts are low.
Individuals with allergies should avoid certain garden chores that aggravate
their symptoms, such as working in the compost pile, working with mulch or
straw, raking, using power blowers, or mowing lawns. Mowing grass can cause
grass particles, pollen, and mold to become airborne.
Don't plant trees, grasses, or shrubs that cause allergies. Choose plants
that are insect-pollinated instead. Keep grass trimmed so it doesn't flower. If
allergies prevent you from mowing, it may be wise to invest in a yard care
service or reduce your lawn area by adding flower beds or ground covers.
Eliminate weeds from the garden early, before they reach maturity and flower.
Certain species of the compositae plant family, such as mums, marigolds, and
dahlias, may be cross-reactive for individuals with ragweed sensitivity.
Your doctor or allergist may also recommend medications to help alleviate
allergic reactions. For gardeners with hay fever, new antihistamines are
available that can relieve symptoms without causing drowsiness, hyperness, dry
mouth or eyes, or upset stomach. These non-sedative antihistamines come in many
forms that are taken once or twice a day, in pill or liquid form. Eye drops can
relieve itching, swelling, and irritation. Nasal sprays come in both non-steroid
and corticosteroid forms, and can effectively reduce allergic reactions. These
treatments can ease pain after gardening, but are much more effective when taken
as a precaution before gardening activities - and allergy symptoms - begin.
For gardeners with asthma, your doctor or allergist can recommend one of many
different types of medications, in oral or inhaled form, to treat your
condition.
Allergy shots or vaccinations can desensitize allergies. These treatments may
be difficult and time consuming, but they allow an individual to build up a
tolerance to allergens, which is helpful to not only treat the symptoms but also
the allergy itself.
Before considering these treatments, consult with your doctor or allergist to
discuss possible benefits and side effects.
Trees and shrubs
ash (male)
cottonwood
elm
Juniper/cedar
maple (male)
mulberry
oaks
pecan and walnut
poplar (male)
privet (male)
Russian olive
willows (male)
Grasses, flowers and weeds:
Bermuda grass
Kentucky Bluegrass
orchard grass
Timothy grass
castor bean
ragweed
pigweed
lamb's quarters
Prepared by Mary Predny, Project
Director: Diane Relf
Reviewers: Dawn Alleman, Jason
Fox, Pamela Teaster
Publication Number 426-067, Posted
July 2002
