Hard to get rid of grassy-type weeds
Dallisgrass
Dallisgrass is a warm season, deep-rooted bunchgrass that spreads by
seed and by short rhizomes left in the soil after trying to pull it
out by hand. It begins growth in very early spring and prefers warm,
moist areas and high-cut lawns. It often infects bermudagrass as well
as other warm-season grasses. It is very difficult to control. 
Dallisgrass requires 3 applications of MSMA in 7-10 intervals. We offer
a seasonal warranty on this treatment.
Nutsedge
At first glass, nutsedge looks like grass, but their stems are triangular
and leaves are arranged in threes from the base of the plant (grass
leaves are in twos along a round stem). They prefer poorly drained,
rich soil and thrive in frequently watered lawns. In summer, they grow
faster than the lawn and quickly stand above it. Very difficult to control.
We apply 2 applications of Manage, 14-30 days apart. We offer a seasonal
warranty on this treatment.
Field Sand Burs
Grow anywhere from 6 to 24" tall and forms low mats in mowed
lawns. It has narrow yellow blades, may be rough on the upper surface.
As an abundance of burrs with extremely sharp spines. While difficult
to control, we have had some luck with a special pre-emergent herbicide
if it gets applied in early spring.
Blue Stem
Can be treated the same as Dallisgrass