College of Agriculture & Natural Resources

• Birdsfoot Trefoil

  Birdsfoot trefoil is a common perennial broadleaf plant in under-fertilized, minimal maintenance turfgrass sites. It is well distributed across Michigan and the Great Lakes Region.

• Waitea Patch

  Waitea patch is an emerging problem on annual bluegrass in Michigan. Symptoms typically begin as thin yellow rings, ranging from a few inches to a 1 ft (10 cm to 0.3 m).

• Quackgrass

  Quackgrass is a common grassy weed of turfed areas. Quackgrass is a perennial and can often be spotted by its dull blue-green appearance. Because quackgrass spreads by rhizomes (underground stems) it responds very well to cultivation practices. It is common to have quackgrass contamination in unscreened topsoil. Each rhizome section has the ability to produce a new plant.

• Red Sorrel

  Red sorrel is a perennial weed of low-maintenance sites characterized by dry, infertile and often low pH soils. Red sorrel will survive at neutral pH but is usually not as prevalent because the turf will be more competitive under these conditions.

• Corn Speedwell

  Corn speedwell is an upright, clumping winter annual that produces small purple flowers in the spring. The lower, non-flower, portion of the plant has leaves that are round-to-oblong with rounded teeth on the margin in an opposite arrangement.

• Wild Violet

  Wild violet is a low-growing clumping (simple) perennial with a dense, fibrous root system and heart-shaped leaves that often cup toward the petiole to form a funnel shape. Wild violet is often considered difficult-to-control due to its aggressive growth, waxy leaves and resistance to most common herbicides.

• Yarrow, Common

  Common yarrow is considered a desirable herbaceous perennial by many gardeners and is sold in its cultivated form at most greenhouses.

• Creeping Speedwell

  Creeping speedwell is a low growing perennial that prefers shade, moist soils, good fertility and a low mowing height.

• Goosegrass

  Goosegrass is a warm season summer annual grassy weed that predominates in exposed, trafficked conditions.

• Orchardgrass

  Orchardgrass is a competitive perennial grassy weed of cool-season turf. It has a very well developed fibrous root system and can be difficult to remove once established.

• Perennial Sowthistle

  Perennial sowthistle is common in roadside and low maintenance turf and somewhat less common in landscapes. It prefers slightly alkaline or neutral soils, fine-textured, rich soils. Perennial sowthistle will not thrive on coarse sandy soils.

• Leaf Spot

  Leaf spot is a warm-weather disease, but the pathogen overwinters as dormant mycelium in infected plants and dead grass debris.

• Bermudagrass

  Bermudagrass is a warm-season perennial that spreads by stolons (above ground runners). Bermudagrass is a not widely considered to be cold tolerant, however, several selections exist that can overwinter in Michigan.

• Crown Rot Anthracnose

  Anthracnose can occur as both a foliar infecting and crown infecting disease.

• Field Horsetail

  Field horsetail is most often a weed of landscape beds and low-lying areas. Horsetail can survive in turf, but often will not persist with routine mowing.

• Common Mallow

  Common mallow most often establishes along culverts, fencelines and near foundations. Common mallow forms a clump whorled branches that do not root where they touch the ground.

• Dollar Spot

  Dollar spot is characterized by round, bleached-out or straw-colored spots, ranging from the size of a quarter to the size of a silver dollar. Spots appear as sunken areas in the turf, especially low mown turfgrass.

• Dandelion

  Common dandelion is a simple perennial (no branching) with a basal rosette that has deeply lobed leaves that generally point back towards the center of the rosette. Probably the most common weed in maintained turf.

• Buckhorn Plantain

  Buckhorn plantain is a narrow-leaved perennial that forms a rosette. The 3-10 inch long leaves are less than 1 inch wide and arise from a thick, shallow tap root. Buckhorn plantain is very common in maintained turf but will also survive in meadows and waste areas.

• Prostrate Knotweed

  Prostrate knotweed is a supreme indicator weed. Knotweed is the earliest germinating of all the summer annual weeds. Due to its early germination timing, knotweed is able to claim resources and invade damaged areas before other desirable grasses begin to grow.