Mountain ash trees provide a late-season meal

As leaves fall from the trees, remaining berries are even more obvious and it is hard to miss the orange berries of mountain-ash trees (Sorbus americana). Both wild and cultivated mountain ashes provide late-season food for black bears, American robins, evening grosbeaks, moose and snowshoe hares.

Our native species is a true northwoods tree, ranging from the boreal forest region of northern Minnesota, Wisconsin and Michigan to eastern Canada, New England and the Appalachian Mountains. You can also find the very similar cultivated European mountain-ash in yards across the midwest.

This tree can grow to 30 feet, but you often see it as a shrub in the understory of evergreen or mixed deciduous/conifer forests in the northland. They are easy to miss, except in the fall, when their clusters of orange or red berries add extra color to their yellow leaves every fall.

Common names can sometimes be misleading. The mountain-ash isn’t actually an “ash” tree. It is part of the rose family along with apple trees, cherry trees and plum trees. Mountain-ash leaves are up to eight inches long and contain 13-17 narrow, toothed leaflets, making them look like ash leaves, hence the misleading common name.

You can find these trees scattered in forests, but they are more common on forest edges. They grow well in moist soil, but also grow well in drier soil.

The clusters of bright orange or deep red berries have been ripe for at least a month, but they are so low in fat content that they are not likely to rot before freezing.

Mountain-ashes depend on berry-eaters to spread their seeds. When a bird eats a berry, it flies off and deposits the seed in its dropping. The same thing happens with bears, on a larger scale. This way these small trees can make sure that their seeds get scattered around the forest and land with a ready source of fertilizer (bird or bear droppings).

Bears make “mini-migrations” to feast on these berries before retiring the their winter sleep (bears don’t technically “hibernate” the way that bats and ground squirrels do, but they do sleep through much of the winter months).

Because mountain-ash fruit have low lipid (fat) content, botanists term them a “low-quality fruit.” Birds and other animals will high-quality fruit like Virginia creeper and flowering dogwood before turning to low-quality fruit. This means that we will see colorful mountain-ash berries on the trees well into the winter. Depending on what other foods are available, birds may not get around to eating the berries until February.

So the next time you are out for a walk, look for these orange or red berries in our forests and yards.