Snow in June? Pollen falling from the trees? By Sylvie Maurice

Neither one nor the other. The “flakes” we see twirling through the air in late May or early June carpet our lawns the way the first snow would. In the greater Montréal area, that white moss comes mostly from large cottonwood trees, a type of poplar. Contrary to what a lot of people think, it’s not pollen. What in fact is involved is a small seed attached to long silky hairs resembling cotton. Those hairs allow the seed to be scattered by the wind.

A male or female poplar?

Don’t make a mistake: there’s a big difference – literally – between seeds and pollen. Pollen is tiny and more closely resembles a fine powder barely visible to the naked eye. With poplars, trees are either male or female. Male individuals produce the pollen that, transported by the wind, pollinizes the blooms on female trees. From that union the seed is born. It’s that little poplar seed attached to its “cotton” that you see falling from the sky. The whole thing is known as a tumble fruit or diaspore. The blooms on your poplar aren’t producing “cotton”? Then you’re definitely dealing with a male of the species.

This article was written in collaboration with Pascale Maynard, horticultural information officer at the Jardin botanique de Montréal.

Have any questions relating to this blog?
Consult our Green Pages, or visit the horticultural information counter at the Jardin botanique for personalized service. One of our experts will be happy to give you more information.