Winterberry Holly

It’s the time of year when many Islanders are collecting natural greenery, sticks, and berries for seasonal decorations. Today’s PEI plant is commonly used for its splash of bright colour, but you’ll want to keep it out of reach of children and pets. Meet Winterberry Holly (Ilex verticillata).

You’re likely familiar with its relative, English Holly (Ilex aquifolium), a popular Christmastime symbol (I have fond memories of my Grandmother’s holly-shaped Christmas cookie cutter). Unlike that evergreen European plant, our native Winterberry Holly’s leaves don’t last all winter, but the berries do, making it attractive both in the landscape and for decorations.

Those bright red berries many look enticing, but don’t be tempted to eat them. All parts of the plant – but especially the berries – contain theobromine, a chemical similar to caffeine. Theobromine also occurs in cocoa and chocolate, and is what makes those foods toxic to dogs and cats.

In humans, too much theobromine will cause dizziness, high heart rate, low blood pressure, stomach cramps and nausea; dogs and cats may show lethargy, vomiting, and diarrhoea. (A close relative of Winterberry Holly is named Ilex vomitoria, giving you a clue to the effects!). Ingestion of Winterberry Holly berries is more likely to be unpleasant than fatal, but it’s best to keep them away from little hands and paws.

Despite this toxicity to people and pets, Winterberry Holly is eaten by wildlife – a good reminder that seeing wild birds or mammals eating a plant or fungus does not mean it’s safe for us to do the same! Holly’s persistent berries provide winter food for overwintering birds such as Ruffed Grouse and Blue Jays, and an early spring food source for returning migrants (or stragglers that stuck around) including Robins, Waxwings, and Flickers.

Winterberry Holly is common across the Island, although I find it most often along coastal trails and roadsides. It’s an eye-catching and unmistakeable member of PEI Untamed!