Winterberry: our northern holly

Winterberry: our northern holly

A bright spot of color in winter

Winterberry shrubs are easy to spot in Maine this time of year, when its red berries are often the only bright color on the landscape. Look for it in roadside ditches, in and around wetlands, and in soggy spots in the woods. From March to October this shrub is cloaked with dark, glossy, oval leaves, but in the winter the red berries stand out and draw us to take a closer look.

Unlike its southern relatives, winterberry is deciduous. Sometimes called black alder or northern holly, it ranges from Newfoundland to Michigan and south to West Virginia. It is a tough plant that grows well in average soils and can tolerate regular wet roots. Pests and disease are few, though its leaves can turn yellowish in alkaline soils.

Winterberry spreads not only through seed dispersal but also with suckers and by layering. Layering is when branches are bent down to the soil, as they are by heavy snow, and then sprout roots. Eventually these branches break off and become a new plant. This is why you will often find thick pockets of Winterberry where it has both spread by suckers and layering over time.

An important late-winter food for flickers, crows, robins, and cedar waxwings, these native shrubs are a wonderful backyard habitat enhancement. There are many non-native cultivars now available at nurseries, but be aware that some of these produce berries that seem to be less attractive to birds than native winterberry.

Some friends and I have been discussing the noticeable decline in quantity of winterberry fruits this year, especially compared to last year, and speculating on the reason. Perhaps it was the drought? We don’t know for certain.

Winterberry in a wet roadside ditch in September of 2019, with a plentiful crop of berries visible among the leaves.

Winterberry in winter photo by Nicholas Tonelli.