What Trees Produce the Most Pollen?

Pollen is a natural occurrence from trees as part of their lifecycle. However, pollen can cause major issues for the human respiratory system. Thankfully, there are peak times for pollen and low times for pollen. With some planning, we can treat allergies or avoid high pollen times.

When it comes to pollen, some trees produce large amounts. These trees can cause symptoms for everyone, even if they do not suffer from seasonal allergies. Overall, pollen pollutes the air for us who depend on the environment to breathe. However, pollen production is a natural process that supports the ecosystem.

Knowing the trees with the highest pollen production rate can help you avoid them. If you plan to plant trees in your backyard or garden, you can skip these species, especially if you suffer from seasonal allergies.

These trees may be geographically specific or widespread. Altogether, the trees in our list are the highest producers of pollen and are sure to wreak havoc on your air quality. The pollen from trees is lightweight and incredibly airborne. At peak times, pollen will cover the grass, cars, and roofs.

Generally speaking, entire genera are guilty of highly producing pollen. It is not species specific. Most of the time, all birch trees produce significant amounts of pollen, not just the river birch.

Top 5 Worst Pollen Producers

1. Birch
2. Beech
3. Juniper
4. Elm
5. Hickory

What are the Worst Months for Tree Pollen?

Tree pollen is a seasonal issue. In most states, the months between November and February are low pollen months. The southern states have longer growing seasons because of the warmer climate. No matter the location, the winter months are limited for pollen production.

The worst months for pollen are between March and May. While it seems early, trees produce pollen at the beginning of their growing cycle. That being said, the pollen is certainly at its peak in the spring.

By May, most trees are in full bloom. In some southern states, high pollen seasons can begin in February.

Across the United States, you may need to witness pollen from February to September. However, the peak is in May.

1. Birch

The birch genus contains approximately 50 species. All of which produce significant amounts of pollen. These deciduous trees are easy to identify because of the white bark growing along the trunk. Overall, the bark is like paper and peels off in long strips.

Birch trees are pioneer trees. They take over barren lands giving strength to the soil. Once the birch trees create a stable ecosystem, other plants and trees can move in. Birch trees grow to 70 feet tall with a 35-foot spread.

The pollen from birch trees causes significant respiratory symptoms. Altogether, birch trees produce 5.5 million pollen grains per male tree.

Some common species of birch are black birch, white birch, cherry birch, and yellow birch. These trees grow across the United States. Birch trees can grow in the cold and snowy areas of the northeast and in swampy lands of the southeast. In fact, few species spread to the west coast.

 2. Beech

Beech trees are a stately genus that grows in much of the Northern Hemisphere. There are only 13 species in this genus. The small number of species does not limit the growth of these trees. Altogether, beech trees are tall trees and often reach 80 feet in height. The spread is smaller at 40 feet.

You can identify the beech tree by its thin gray bark. Moreover, the branches grow high on the trunk exposing much of the lower trunk. Long branches grow from the beech tree and many hang low to the ground. With such a large canopy, the beech tree creates excellent shade.

The beech tree produces over 3 million pollen grains per year.

Because of their beauty, arborists and gardeners love to plant beech trees for ornamental uses. However, this results in beech trees growing all over the east coast causing issues for us.

Some common species of beech trees are the European beech and the American beech.

3. Juniper

In the United States, many trees in the Juniper genus are called cedar trees. The trees in this category are heavy pollen producers. Altogether, these trees are large trees though the genus ranges in size greatly. In fact, many juniper trees grow to 130 feet.

The juniper tree displays needle-like leaves on weeping branches. The needles are blue in appearance, giving the juniper a striking look.

In Texas, pollen from juniper trees causes what is known as cedar fever. A massive concentration of junipers in the area leads to a significant accumulation of pollen. The juniper tree produces 400,000 pollen grains per male.

Some common species of junipers are the Mountain Cedar (Ashe juniper), the Eastern red cedar (Virginia juniper), and the Western red cedar (Rocky Mountain juniper). All these trees grow in the southern states. Most of the juniper population does not cross the Rocky Mountains. Overall, the population spreads from the east coast to Texas.

4. Elm

Dutch Elm Disease has decimated the elm population in the United States. However, the remaining population still produces enough pollen to make our list. Elm trees are still prevalent in much of the Midwest and eastern United States.

As we gain control over Dutch Elm Disease, the population of elms is returning. The elm genus contains approximately ten species today. Most species grow to 80 feet tall, but some ancient species reached 110 feet tall.

Elm trees display large canopies with large leaves with jagged edges. The bark is dark brown and deeply furrowed.

Some common species of elm are the American elm, the cedar elm, and the Chinese elm.

 5. Hickory

Hickory trees are tall trees growing in much of the United States. Altogether, most of the population is concentrated in the Midwest and the southeast. However, some species travel into the southwest and the northeast.

Overall, there are twelve species native to the United States. These trees produce large nuts that animals depend. The leaves are oval and dark green. Additionally, the bark is deeply furrowed and gray.

Many hickory trees grow to 100 feet tall. True hickories cause some allergenic symptoms because of their pollen production. On the other hand, the pecan hickories are much worse. These trees produce significantly more pollen amounts than the other hickory species.

Some common species of hickory that cause pollen issues are the pecan hickory, shellbark hickory, and shagbark hickory.