Plant identification is high on our list of activities at our UI Extension offices. Generally the question accompanying the plant sample is "Is this a wildflower or a weed?" My answer, "Well it depends on whether you like it or not". A weed is described as "a plant out of place" or more optimistically philosophical "a plant whose virtues are yet to be discovered". Plants are not inherently wicked weeds. We decide by our wants and needs on whether a plant is a weed. For example the violet is the Illinois state flower yet it appears on herbicide labels.
A plant's goal in life is grow, flower, seed, repeat. I doubt if world domination is on their to-do list. Although I am starting to wonder about teasel as it marches along every interstate highway. Some plants are excellent opportunistic invaders as we mow, till and move soil and plants around.
A common plant we identify in yards and gardens is Star-of-Bethlehem (Ornithogalum umbellatum). It's an ornamental native to Europe that quickly "went rogue" beyond the boundaries of gardeners' desires. To behold its delicate white flowers in May it's hard to imagine it is anything but a lovely wildflower. Unfortunately it does very well in its ability to spread into every nook and cranny of our yards and even into fields and furrows through its seeds and prolific production of small bulbs that arise from the parent bulb. If that weren't enough, Star-of-Bethlehem is also poisonous. All parts of the plant contain cardiac glycosides, so no grazing in your garden.
Star-of-Bethlehem leaves appear early in the season as thick clumps of succulent narrow leaves. The tufts of green sometimes completely cover garden beds. Leaves are a bright grassy green color with a whitish stripe along the top midrib. At first appearance they may be mistakenly identified as wild onion or wild garlic. However wild onion and wild garlic emit a strong onion smell when leaves are crushed; whereas, Star-of-Bethlehem has no strong odor. In May crocus leaves look similar with a white stripe but are coarser, and not as succulent and certainly not as prolific.
In May Star-of-Bethlehem produces white star-shaped, six-petaled flowers. The back sides of the petals also possess a green stripe. Flower stalks appear as the leaves start to turn yellow. By mid-summer the leaves and flowers have yellow and died; however, the prodigious population of bulbs lurk in the soil waiting to arise again next year as we curse or cheer.
If you have decided Star-of-Bethlehem is on your weed list, your best bet in control is digging the bulbs, preferably early in the season as leaves appear. Anticipate a long term commitment to this plant eradication method. Obviously don't put bulbs in the compost pile or send to landscape recycling. After digging Star-of-Bethlehem I put the bulbs in a small black plastic bag near my garden shed. In a year they became unrecognizable goo ready for adding to my compost. Herbicides containing glyphosate sold as Round up® provide little control.
In lawns Star-of-Bethlehem also resists control using herbicides. Their new spring leaves are most susceptible to herbicide injury. Herbicides that may provide control are sulfentrazone or carfentrazone. Sequential applications according to label directions may be necessary for complete control. Check the label for number of days to delay mowing following application to allow herbicide uptake. Always read and follow all label directions. Check out UI Extension's Home, Yard and Garden Pest Newsletter for more information on management http://hyg.ipm.illinois.edu/article.php?id=448
Whether it's a wildflower or weed accurate identification is helpful. Check out University of Illinois Wildflowers website http://extension.illinois.edu/wildflowers/ Join me Tuesday May 17, 2016 at 6pm at the Danville Public Library as I discuss invasive plants. You are welcome to bring your wildflower or weed plant samples for identification.