Grass seed typically takes between 5 to 30 days to germinate and start growing, with the exact time depending on the grass type, weather conditions, soil preparation, and moisture levels

. Germination times by grass type:

• Cool-season grasses generally germinate faster:
  • Perennial ryegrass: 5 to 10 days
  • Fine fescues: 5 to 14 days
  • Tall fescue: 7 to 14 days
  • Kentucky bluegrass: 10 to 30 days
• Warm-season grasses usually take longer:
  • Bermudagrass: 10 to 30 days
  • Zoysiagrass and Centipedegrass: 14 to 21 days
  • Buffalograss: 14 to 30 days

Other factors influencing germination time:

• Soil temperature: Cool-season grasses germinate best between 50°F and 65°F (10°C to 18°C), while warm-season grasses prefer 65°F to 75°F (18°C to 24°C)

• Moisture: Consistent soil moisture is essential; seeds must not dry out but also should not be waterlogged

• Soil quality: Well-prepared, loose soil with proper pH and good drainage speeds up germination

• Time of year: Cool-season grasses are best planted in early autumn or spring, warm-season grasses in late spring to early summer to match optimal soil temperatures

• Light and oxygen: Seeds need to be planted at the right depth to access light and oxygen for healthy sprouting

Once germinated, grass typically grows about 2/3 cm per week and can take 8 to 12 weeks to reach mowing height under good conditions

. In summary, expect grass seed to start growing within about one to two weeks on average, but it can vary from as little as 5 days up to a month depending on species and environmental conditions.