Science, Tech, Math › Animals & Nature What Types of Pollen-Producing Trees Cause Allergies? Pollen Producers You Can Live With — and Those You Can't Share Flipboard Email Print MIXA / Getty Images Animals & Nature Forestry Tree Structure & Physiology Tree Identification Basics Arboriculture The Science Of Growing Trees Conifer Species Individual Hardwood Species Pests, Diseases, and Wildfires Tree Planting and Reforestation Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Dinosaurs Evolution View More By Steve Nix Forestry Expert B.S., Forest Resource Management, University of Georgia Steve Nix is a natural resources consultant and a former forest resources analyst for the state of Alabama. He is a member of the Society of American Foresters. our editorial process Steve Nix Updated July 26, 2019 Plants that produce wind-blown pollen, many of which are trees, make life miserable for millions of human allergy sufferers each year. A large number of tree species produce extremely small pollen particles from their male sexual parts. These trees use the wind as their favorite means of pollen transport to others of their own species for pollination. This pollination leads to the procreation of new trees. That's a good thing. Pollination is critical for trees to reproduce but can be crippling to some people with specific tree allergies and asthma. If these allergy sufferers live in areas with lots of the wrong trees, there can be major health issues and loss in quality of life during peak pollen season. Allergy sufferers can make it through tree pollen season with a minimum of discomfort by following some common sense suggestions. Minimize outdoor activity between 5 and 10 a.m., as morning is the time when pollen counts are usually the highest. Keep the house and car windows closed and use air conditioning to stay cool. But you don't have to stay inside all the time either. You need to have an awareness of the kind of trees you live near or the trees you plant that produces small-sized pollen. Certain trees can become a major allergy problem. It is your understanding of this, in combination with a knowledge of allergy-producing trees, that can help make the difference between an itch and sneeze-free day or a day of complete misery. Pollinating Trees To Avoid There are a number of trees to avoid if you are allergy-prone — and they are not necessarily a single species but usually a single sex. The allergen that triggers your allergy is usually produced by the “male” part of a tree. Trees vary widely in their capacity to produce and disperse pollen which triggers allergies and asthma. Some tree species that bear separate male and female flowers on the same plant are called "monecious." Examples include honey locust, oak, sweetgum, pine, spruce, and birch. You can't do much but deal with these as a species. "Dioecious" tree species bear male and female flowers on separate plants. Dioecious trees include ash, boxelder, cedar, cottonwood, juniper, mulberry, and yew. If you select a male plant you will have problems. From an allergy perspective, the worst trees you can live around are dioecious males, which will bear only pollen and no fruit or seed. The best plants in your environment are dioecious females as they bear no pollen and are allergen-free. Trees to avoid are male ash, pine, oak, sycamore, elm, male boxelder, alder, birch, male maples, and hickory. Things You Can Do to Avoid a Problem Plan your landscape: Minimize exposure to known allergens by not planting and eliminating certain allergy-causing trees from your property.Plan your time outside: In order to minimize exposure, plan outdoor activities to coincide with times when the pollen count is lowest.Keep up with the pollen count: Follow the local pollen index (the number of grains per cubic meter of air) that will alert you to days when your particular allergens are most prominent.Allergy skin testing: Using the scratch or blood test for allergies can help you determine what type of pollen allergies you have. Pollinating Trees You Can Live With Obviously, the fewer allergenic trees in an individual's immediate vicinity, the less the chance of exposure. Good news is that the great majority of wind-borne pollen grains of all species are deposited quite close to their source. The closer to the tree the pollen stays, the less potential they have to cause allergy. Remember, a pollen-producing tree or shrub next to a home can create ten times more exposure than a tree or shrub one or more houses away. Get those high-risk trees away from your home. One rule of thumb: flowers with large blooms usually produce heavy (large particle) pollen. These trees attract insects that transport pollen and do not depend on wind transportation. These trees are generally lower in their allergy potential. Also, "perfect" flowers on trees are desired. A perfect flower is one that has both male and female parts in a single flower — not just male and female parts on the same tree. Perfectly flowered trees include crabapple, cherry, dogwood, magnolia, and redbud. Trees that are considered to cause fewer allergy problems are:Female ash, female red maple (especially the "Autumn Glory" cultivar), yellow poplar, dogwood, magnolia, double-flowered cherry, fir, spruce, and flowering plum.