Identification:
Leaves: Leaves are narrow, dark green and and grass-like. They emerge in the early spring
Flowers: The flowers emerge shortly after the leaves in early spring. Flowers are an intense royal blue and each stalk supports one to three flowers. Individual flowers can be one inch across with 6 blue petals and a single dark blue vein running down the middle. Bloom period is 2-3 weeks.
Seeds: Pods start out green but turn brown as they mature. The bumpy, roundish seed capsules contain several reddish-brown seeds each which they release by bursting.
Roots: Siberian Squill grows from a bulb, during the summer, fall and winter, the dormant bulbs are covered in a loose dark tunic.
Reasons Siberian Squill is a Problem:
- Siberian Squill is a very hardy wildflower, easily able to withstand late cold snaps bringing snow and freezing temperatures.
- Siberian Squill is not bothered by voles, chipmunks, rabbits, or deer.
- Siberian Squill handles high levels of disturbance well, often resprouting after being uprooted.
Other Information:
Siberian Squill is was introduced to North America from Eurasia and continues to be cultivated, as it has been since 1796. It is one of the very first flowers to bloom after the snow melt in early spring, and is easily identified, often growing in large clumps. Siberian Squill requires abundant sunlight but is often found as a ground cover in woodlands, growing early in the spring before trees are leafed out. Squill conducts all it’s growing early in the spring and dies back once the forest trees are fully leafed out. It is very commonly found in residential gardens and yards, from which it has spread to the Arboretum. Siberian Squill has the potential to crowd out native wildflowers but currently there are not any known control measures that would not impact native plants growing in the area. Arboretum staff are monitoring its presence in the arboretum and hand dig very small populations to avoid it getting established in any of the high quality native plant communities where it does not currently occur. There are acres of forested areas in the Arboretum that are infested with this plant.
Cowling Arboretum Procedures for Removal:
The Cowling Arboretum currently limits Siberian Squill removal to finding and digging small patches in otherwise high quality sites. We have tried several herbicides (glyphosate and triclopyr) in highly infested areas for two years running but have had no success We did not use a surfactant and applied at the recommended concentration from the label. Squill is difficult to control in natural settings by digging as the small bulbs are deep in the soil and many seeds are produced.