Description

Dallisgrass (Paspalum dilatatum), field paspalum (Paspalum laeve), and thin paspalum (Paspalum setaceum Michx.) are common perennial weeds in turf, and are some of the more difficult-to-control weeds. All three species resemble each other very closely, and field paspalum and thin paspalum are often mistakenly called dallisgrass. Thin paspalum has a glossier, more shiny leaf when young than dallisgrass. Dallisgrass leaf appearance is very similar to crabgrass, which is a dull green appearance.

Cultural Control

Dallisgrass, like other perennial paspalums, is one of the more difficult-to-control weeds in turfgrasses. Perennial grass weeds such as dallisgrass are not desirable as turfgrass species under any conditions. Therefore, every effort should be made to prevent these weedy grasses from becoming established in turf, as selective control measures are usually difficult. Maintaining a dense, healthy turf year round by proper mowing and fertilization helps prevent encroachment and weed establishment.

Species Data

• SEEDHEAD / FLOWER
  • raceme; hairy spikelets arranged in 4 rows on 3 - 8 alternate branches on tall (up to 5 feet in unmowed situations) terminal stalks
    ​Figure 1, Figure 2, Figure 3, Figure 4
• VERNATION TYPE
  • leaves rolled in the bud
    Figure 5
• LIGULE TYPE
  • membranous; up to 0.2 inches (5 mm) long, sharp pointed to blunt
    ​Figure 6, Figure 7
• GROWTH SEASON / LIFE CYCLE
  • perennial weed
• AURICLE TYPE
  • absent
    ​Figure 8, Figure 9
• LEAF BLADE TIP SHAPE
  • sharp-pointed; flat, sharply creased, not hairy or with a few hairs at base, hairs behind ligule, edges smooth or rough
    Figure 10
• LEAF BLADE WIDTH
  • 0.28 - 0.6 inches (7 - 15 mm) wide
• STOLON PRESENCE
  • absent
• RHIZOME PRESENCE
  • present; occasional and very short
• COLLAR TYPE
  • continuous; not hairy, often hairy on edges
    Figure 12, Figure 13, Figure 14, Figure 15
• SHEATH MARGIN
  • split with overlapping margins
• SHEATH TYPE
  • flattened; sheath is not densely hairy, often has long hairs near base of plant; slightly creased