This grassy weed often goes undetected in lawns until its unusual texture precedes it crowding out desirable turfgrass. 

Annual Bluegrass Facts:

• Most noticeable in early spring
• Winter annual weed
• Clumping growth habit with patches joining to create larger stand
• Seeds at a height below most mowing heights
• Prefers to grow in compacted soil
• Each plant produces 300+ seeds

Control Tips:

• Spot-spraying areas with a selective herbicide have very minimal results. In some situations, a fall pre-emergent herbicide can minimize growth. However, this weed can develop resistance to most of these materials. 
• Thick turfgrass areas will yield fewer weeds. Fertilize regularly, aerate and overseed each fall.
• Mowing at 3-4" will encourage a healthy lawn and reduce weed growth. 
• Irrigate lawn areas regularly so they receive 1-2" of water each week. 
• Proactive, comprehensive lawn care programs are recommended for best control.

Image source: annual bluegrass