Toxic invasive plant is now blooming across Ontario and could harm you and your pets

As the weather continues to warm up in Ontario, you might notice a vibrant blue flower starting to pop up in your garden, on lawns, or in wooded areas, and while it might look like a welcome sign of spring, the toxic plant is best admired from a distance.

Siberian squill (Scilla siberica) is a striking plant known for its bright blue, bell-shaped flowers, and it is among the first species to emerge each spring. Originally introduced to Canada from Russia in the 1800s as an ornamental plant, the species has since spread widely across Ontario and is now considered invasive.

The plant usually begins growing in late March to early April, first appearing as clusters of grass-like leaves before producing its mesmerizing blooms. Each flower stands at about 10 centimetres tall, often appearing in dense patches, with individual bulbs producing a few stems. 

Although blooms usually last for two to three weeks, the plant's resilience is what makes it particularly problematic. The species tolerates disturbances well, can quickly resprout if uprooted, and is not affected by animals like deer, rabbits, and chipmunks.

Recent sightings have already been logged across Ontario on platforms like iNaturalist, a biodiversity social network.

Multiple sightings of the invasive species in southern Ontario have already been logged this spring. Photo: axqrk/iNaturalist.

If left unmanaged, Siberian squill can quickly take over an area and crowd out native plants. Besides its impact on ecosystems, the plant also poses risks to people and pets if consumed.

In fact, all parts of Siberian squill, including its leaves, flowers, bulbs, and seeds, contain compounds that can be toxic if ingested. In both humans and pets, it can lead to symptoms such as nausea, vomiting, and diarrhea. Even handling the plant can also cause skin irritation for some individuals.

Another sighting reported in southern Ontario this past week. Photo: heggieastro/iNaturalist.

To help limit its spread, experts recommend removing or mowing the flowers before they develop seed pods, as well as digging out the bulbs. The City of Toronto also advises tamping down soil after removal to reduce disturbance, which can otherwise encourage more regrowth.

Overall, the most effective way to manage the plant’s spread is to avoid planting it in your garden altogether.