Star-of-Bethlehem is an ornamental plant that has escaped cultivation to become a weed that occurs primarily in minimum- or no-till fields (Figure 1), pastures, and lawns. This plant is a perennial from a bulb (Figure 2) that grows throughout the winter months and completes its life cycle in the spring. It most often occurs in clumps and is one of the few plants that has a dark green color during the winter months when most other plants are dormant and brown. Because of this, star-of-Bethlehem is often misidentified as either wild garlic (Allium vineale L.) or wild onion (Allium canadense L.). However, star-of-Bethlehem does not have a garlic- or onion-like smell like these other weeds. Star-of-Bethlehem also has leaves with a distinctive white midrib unlike either of these other species (Figure 3) and produces small white, six-petaled flowers that typically appear in late-April to early-May (Figure 4).
Figure 1 A dense clump of star-of-Bethlehem plants in a no-till corn/soybean field in late-March in Missouri.
Figure 2 Star-of-Bethlehem produces underground bulblets that lead to dense infestations of this species in subsequent years.
Figure 3 Star-of-Bethlehem has leaves with a distinctive white midrib which helps to distinguish this species from either wild garlic or wild onion.
Figure 4 Star-of-Bethlehem has flowers with six white petals that typically appear in late-April to early-May.
Recently, I've received a few calls on how to control this species prior to corn or soybean planting. I had done a little work on this species a long time ago but more recently, weed scientists at Purdue published some more extensive results on the control of this species. Collectively, what I have learned from all of this is that the best timing for herbicide applications is when plants are in the vegetative stage of growth, approximately three weeks prior to flowering. This would correspond to the stage that most of the plants I've seen in Missouri are in right now. Unfortunately, most of the herbicides that are commonly used in many of our standard burndown programs like glyphosate and 2,4-D offer very little control of Star-of-Bethlehem. Glyphosate plus 2,4-D will only provide about 50% control at best and by one year after treatment, there will virtually be no long-term control of the population. Ironically (and a little bit bewildering at least to me), some of the best herbicides for the control of this perennial species are contact, "burning" herbicides like paraquat (Gramoxone, etc.), flumioxazin products (Valor, Fierce, etc.), and sulfentrazone products (Authority, etc.). But paraquat is the clear winner. While the flumioxazin and sulfentrazone type of products can provide an acceptable level of burndown this season, they are not likely to provide as good of long-term control of the bulblets and the population as an application of paraquat.