P&PDL Picture of the Week for
March 31, 2008

Do you have Wild Onion in your lawn? Or possibly the Star-of-Bethlehem??

Glenn Hardebeck, Turfgrass Research Agronomist, Department of Agronomy, Purdue University

Initially field identified as wild onion, this weedy grass-like plant was received during the first week of March for an ID confirmation. Wild onion is common across the state and is currently showing itself quite well in turf areas, but in this case, the sample turned out to be Star-of-Bethlehem. Star-of-Bethlehem is often mistaken for wild onion or even some type of grass early after it emerges due to its narrow, thick, up-right leaves. It develops from a shallow bulb which readily distinguishes it from grasses, but this characteristic is very similar to wild onion. To distinguish between wild onion and Star-of-Bethlehem before flower formation, a closer examination of the leaves is in order. The leaves of wild onions roll together to form a closed straw-like structure that is hollow on the inside just like our familiar green onion. Within a few days of emergence, Star-of-Bethlehem leaves begin to form a roughly “U” shape with a light-green to white line down the center inside the “U”. Within a couple of weeks the Star-of-Bethlehem will form a white flower with six petals.

Unfortunately, the Star-of-Bethlehem is difficult to control. Herbicides have little effect. Some intense homeowners have had a measure of success pulling the plants being sure to remove the bulbs as well. For most of us, it is likely better to increase our mowing frequency to keep the weedy leaves down at the same height as the surrounding turf leaves and enjoy the white flowers for a couple of weeks in the early spring.

Click images to enlarge

Star of Bethlehem

Wild Onion

Both develop from underground bulbs early in the spring.

Star of Bethlehem leaves are slightly U-shaped with a light-green to white line down the inside center.

Wild Onion's leaves roll together forming an enclosed hollow structure much like a drinking straw.

 

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service