Many lawn weed species are common to northeastern Pennsylvania. Lawn weeds aggressively compete with turf grass for sunlight, nutrients and space on your lawn. Weeds are loosely defined as any unwanted plant and are classified as either broadleaf or grasslike based on their appearance.
Yarrow (Achillea millefolium) is a broadleaf, summer perennial with fernlike scented leaves extending perpendicular from the central stem. White flowers are visible on yarrow from early spring to mid-summer. Physical removal or post-emergent herbicide application are the best methods of removal.
Yellow foxtail (Setaria glauca) is a grasslike, clumping annual that germinates in early summer when soil temperatures reach 65 degrees F. Yellow foxtail propagates by seeds that are produced and dispersed on seed head pods. The best method of prevention is lowering the cut height of your lawn mower to limit the production of seed pods.
Woodsorrel (Oxalis corniculata) is a broadleaf, summer perennial with lobed, heart-shaped leaves ranging in color from green to red to purple. Yellow flowers form in clumps at the end of thin stems and produce the seeds necessary for propagation. Woodsorrel can be effectively hand pulled when the plant is young and immature.
Spotted spurge (Euphorbia maculata) is a broadleaf, summer perennial with lobed, green leaves forming in dense, erect clumps. The flowers are small, green and inconspicuous and bloom between June and September. Dense, healthy stands of turf grass combined with the use of a pre-emergent herbicide will help keep this fast spreading and resilient weed in check.