By Joe Zeleznik, Forester

NDSU Extension

A few years ago, I picked up beekeeping as a hobby. To be honest, I’m not a very good beekeeper. Mostly, the bees keep themselves.

The honeybees, along with myriad native insects and even a few bird species, are critical partners in helping trees reproduce. In general, the trees produce a sweet nectar for the animal, while the animal moves around pollen for the plants.

And sometimes the insect will take some of the protein-rich pollen for its own use. It’s nature’s own win-win situation.

Trees with showy flowers are primarily insect-pollinated. The chokecherries and juneberries in my yard are a classic example of this setup. But there are others.

The first showy-flowered shrubs I see each year are the forsythias. They have bright yellow flowers, and I saw some blooming just a few days ago. I also saw some dandelions at the same time.

My favorite tree-flower is from the northern catalpa, a tree native to the eastern U.S. Catalpa has clusters of large, multicolored, trumpet-shaped flowers. These are primarily pollinated by bumblebees and, surprisingly, moths.

Northern catalpa trees do well in the southern third of North Dakota but might struggle as we move further north. They need a protected site and could likely use some supplemental water to perform best.

While insects do a great job pollinating trees and other plants, some tree species pollinate best by simply using the wind.

American elm is one of the first trees to flower in the spring, and it’s wind-pollinated. Our native boxelder, willows and aspens are close behind. Some have been blooming for two weeks, and the elms are already producing seeds.

One group that flowers a little bit later are the spruce trees. The tiny pink-purplish cones are produced at the branch tips, even before the tree starts growing new leaves. 

The big challenge with wind-pollinated trees? All that pollen in the air can be tough on some people, and I’m one of them (ironically, I’m actually allergic to cottonwood pollen).

The result of all this activity is fruit – the plant reproduces and can spread its genes via the next generation. While we can eat the chokecherries and juneberries, I wouldn’t recommend trying the catalpa fruit. It’s a long, bean-shaped pod with thin, papery, winged seeds.

In all this discussion of the birds and the bees, the birds have been mostly left out so far.

Yes, there are several examples of birds pollinating trees and other plants, though they’re usually specialists. In our own yard, the ruby-throated hummingbirds love our Dropmore Scarlet honeysuckle vine.

Okay, that’s not a tree. But its flowers, and the hummingbirds, are beautiful!

NDSU Agriculture Communication – April 28, 2026

Source: Joe Zeleznik, 701-231-8143, joseph.zeleznik@ndsu.edu

Editor: Dominic Erickson, 701-231-5546, dominic.erickson@ndsu.edu