Eastern cottonwoods are shedding innumerable seeds that are blown around by the wind on their cottony down.

Now, as the seed pods of the female trees burst and the minute, silky-haired seeds fall, it reminds us of thistle and milkweed down. Also, the cotton collects along curbs, looking snow-like.

Cottonwoods usually grow in moist lowlands near rivers and streams, and along lake shores and other moist slopes. This tall tree species is widespread and important east of the Rocky Mountains. In Minnesota, the majority of cottonwoods are found in the southern half of the state. Pioneers brought eastern cottonwoods to the treeless prairies, and the species is still used as windbreaks and shade trees around farms on the plains. Shade is provided by a broad crown filled with shiny, green, triangle-shaped leaves that rustle easily in the wind. The rustling to me sounds like a gentle rainfall.

Being a fast-growing tree, a 15-year-old cottonwood could be 60 feet, but at a little more than 100 feet it reaches its limit of growth. Its life span is short. At 75 years it is an old tree, subject to decay, and 125 years is exceptionally old for a cottonwood. The wood is light and soft, warps badly while drying and is difficult to split. Nevertheless, it is used for crates, packing material, paper pulp and firewood. Some birds and squirrels eat the cottonwood buds. Warbling vireos and Baltimore orioles sing from its branches. Woodpeckers make cavities where they and other birds to follow raise their young and find winter shelter. Raccoons look to old cottonwoods for hollows. And insects and other tiny creatures hide in the tree bark.

Jim Gilbert taught and worked as a naturalist for 50 years.