Allergy Handbook

Allergy and The Environment – An Arizona Handbook

The Arizona Allergy and Asthma Society is an organization comprised of board-certified and board-elligible Allergy/Immunology specialists in Arizona. One of our goals is to serve as a resource for allergy information to the Arizona public. This is achieved by providing Arizonians with the “Allergy and the Environment, An Arizona Handbook.” On online version of this handbook is available below.

Plants & Landscaping

What are good plants for allergy sufferers?

PLANTS FOR ALLERGY SUFFERERS

by William E. Miller, M.D.

If you or someone in your family has allergies it is desirable for the vegetation around your home to have as low a potential for allergic sensitization as possible. Since most pollens are light and may blow many miles this will not totally solved the problem. However, pollens are the light…the further you are from the source, the less you get! Therefore it is worthwhile to use plants with low potential for sensitization when planting vegetation around the home.

Not all plants that will grow in Arizona have been evaluated from the standpoint of their allergic potential. There is some disagreement among allergists as to which plants are best. A good general rule to follow in evaluating a plant is that if it has an attractive flower, it is probably an insect-pollinated plant. Pollen on insect-pollinated plants is heavy and sticky, and not likely to blow around since it is designed to stick to bees, butterflies, and the like. In contrast, if the flower is small, inconspicuous, or seemingly nonexistent, you probably have a wind-pollinated plant. Since wind pollination is very inefficient, these plants must produce large quantities of small and light pollen to be effective. These, then, are the plants most likely to cause allergies, since their pollens are present in the air in large quantities and are readily inhaled.

Some plants are mixed wind and insect pollinated—palo verde is an example. The pollens of plants such as fruit trees and citrus do no cause allergies, but the strong, sweet odor of their flowers may bother allergic individuals. Below are some plants that do well below 3,500 feet and are generally accepted as having low potential for bothering allergy prone individuals.

What are some low allergy plants?

LOW ALLERGY PLANTS

by Suresh C. Anand, M.D.

Suggestion for low-allergenic trees, grasses, and shrubs:

TREES

  • African Sumac *
  • Aleppo pine *
  • Bottle brush
  • Bottle tree *
  • Citrus
  • Eucalyptus
  • Jacaranda
  • Natal Plum
  • Orchid tree
  • Pepper tree
  • Silk tree
  • Palm * (California and Mexican fan palms)

GRASSES

  • Dichondra
  • St. Augustine
  • Tif or other hybrid Bermuda grass

You should check with a nursery for the best choice.

SHRUBS

  • Any flowering shrub
  • Bougainvillea
  • Cat’s Claw *
  • Cactus and succulents *
  • Ivy *
  • Mexican bird-of-paradise *
  • Oleanders *
  • Privet
  • Pyracantha *
  • Yucca

All of the above plants do well in the desert and are easily available. Plants marked with a * are “star performers.” Citrus and other fruit trees and vegetable plants usually do not cause any problems as their pollen is not airborne. Oleanders themselves do not cause inhalant allergies, but pollen and molds may collect on them and disperse during windy weather.

Bermuda grass and olive trees are two of the biggest offenders. Swan Hill olive trees seem to cause no problems.

What plants or landscaping can aggravate allergies?

ALLERGENIC LANDSCAPE PLANTS

by Geraldine Freeman, M.D.

Certain trees and grass for landscaping have a known potential for production of highly allergenic pollens. The closer to the windows and doors of a home or office these grow, the greater will be the exposure indoors. A closed home still allows the entry of pollens through cracks.

Low to middle elevation deserts (up to 4,000 feet, including Phoenix and Tucson): Bermuda, Kentucky blue, annual rye (but not perennial or “winter” rye), fescue, salt, fountain, and pampas grasses; ash, tamarix (salt cedar), elm, juniper or cypress, mesquite trees, male mulberry trees, European olive, as well as pecan, privet, sycamore, black walnut, and possibly palm trees.

High middle desert to high mountainous terrain (above 4,000 feet); Any of the above trees and grasses have allergenic potential. In addition, there are pasture grasses (barley, brome, oat, orchard grass, timothy, and wheat), ailanthus (tree of heaven), aspen, alder, birch, maple or box elder, poplar, and oak trees. It is assumed that Russian olive (not in the true olive family) is allergenic.

Willows are not believed to contribute much allergenic pollen to the environment. Fortunately, given their numbers, pine trees and eucalyptus trees are seldom allergenic.

Allergy and the Environment