Dandelion (Taraxacum officinale)
Dandelion is a cool season perennial that reproduces by seeds and root pieces. Dandelions emerge above a long, sturdy tap root to form basal rosettes of narrow, deeply lobed leaves. These leaves are 2 to 10 inches long and up to 2 1/2 inches wide. They have jagged lobes that point back towards stem. Dandelion inflorescences are yellow, up to 2 inches in diameter, and appear to be solitary. They are borne on hollow stems that can grow up to 20 inches long, and held above the foliage. The inflorescences ripen to become round "puffballs" of wind-dispersed seeds. Flowering period is from early spring to late fall.
Dandelions occur in most lawns throughout the growing season, especially thin turf areas.
To control dandelions without chemicals, maintain turf density and health using proper culture; mow often to remove seed heads before seed maturation, and mechanically pull removing as much root as possible.
Apply postemergence herbicides during periods of active growth in mid spring to early summer and/or mid to late autumn; preemergence herbicides should be applied before seed germination.