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Bulb-Forming Weeds in Turf

April 28, 1999
Star-of-Bethlehem and wild garlic are two bulb-forming weeds that commonly invade turf areas. Star-of-Bethlehem (Ornithogalum umbellatum), also known as summer snowflake and starflower, is a common early-spring weed problem that occurs throughout Illinois. A member of the lily family, star-of-Bethlehem is a perennial bulb-former that has escaped old ornamental beds to invade lawns and also landscape and waste areas. Seed propagation is rare; it is primarily spread by small bulbs or bulblets. It is reported that all parts of star-of-Bethlehem are poisonous.

Description: The oval bulbs of star-of-Bethlehem are 1/2 to 1-1/2 inches long with fibrous roots at the base. Commonly, the bulbs will increase to form clumps. In early spring, tufts of fleshy, dark green linear leaves, approximately 4 to 12 inches long and up to 1/4 inch wide, emerge from the ground. Each leaf has a light-colored midrib. Shortly after the leaves emerge, branched, leafless flower stalks (scapes), similar in length to the leaves, appear. At the end of each branched stalk is a star-shaped flower appearing to have six white petals, each with a green stripe on the underside.

Control: Controlling star-of-Bethlehem is difficult; it emerges, flowers, and dies to the ground early in the spring growing period. A perusal of weed-control literature failed to identify any labeled chemical control options. Digging, drying, and discarding the bulbs is the most commonly recommended control practice. Occasionally, spring beauty (Claytonia virginica), a similar species, is mistaken for star-of-Bethlehem. Spring beauty is a member of the purslane family and is a commonly found Illinois native. It emerges from fleshy, tuberous roots and produces elongated leaves approximately 6 inches long and 1/2 inch wide. Individual flowers of spring beauty have five petals (star-of-Bethlehem flowers have six) and are white tinged with pink. They occur in branched inflorescences at the ends of flowering stalks and usually bloom during March and April. Spring beauty is often found in moist woods or shaded areas.

Like star-of-Bethlehem, wild garlic (Allium vineale) is a cool-season, bulb-forming perennial member of the lily family that commonly reproduces by aerial and underground bulblets. Reproduction by seed in northern states is uncommon. A strong odor of garlic or onion is produced by all plant parts when smashed. Wild garlic is commonly found in fertile, poorly drained, fine-textured soils and thin turf areas.

Description: Beginning growth in early spring, the leaves of wild garlic develop from the bulbs into upright, grasslike plants. Stems can grow to more than 3 feet. The leaves of wild garlic are two-ranked, slender, hollow, nearly round, and attached halfway down on a waxy stem. The inflorescence is an umbel, 1 to 2 inches in diameter. The small, greenish white flowers are found on stems above the aerial bulblets. Flowering occurs during May and June. Less common is wild onion (Allium canadense). Wild onion appears and smells similar to wild garlic but has solid leaves.

Control: To control wild garlic without chemicals, maintain turf density and health through proper culture. Mow frequently and mechanically remove all portions of plants. Apply ester formulations of postemergence broadleaf herbicides containing combinations of 2,4-D, MCPP, MCPA, dicamba, triclopyr, or clopyralid during early to mid-spring when weeds are actively growing. (Tom Voigt, Bruce Spangenberg, Bruce Branham, and Tom Fermanian)

Author: Bruce Branham Bruce Spangenberg Tom Voigt Tom Fermanian


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