Prostrate knotweed Polygonum aviculare
Appearance:
Characterized by strong, wiry, stems with blue-green, oblong leaves that radiate from a central tap root. Tiny white flowers appear at junction of leaf and stem. See botanical illustration.
Growth:
Forms a low growing mat of foliage. Spreads by seed with seedlings emerging in late winter or early spring. Grows well in hard, compacted soil like heavy traffic areas along sidewalks and driveways.
Physical Control:
Aerate to relieve compaction.
Chemical Control:
Spot spray with post-emergent broadleaf herbicide containing triclopyr, clopyralid, or 2,4-D, MCPP, and dicamba.