Does Kentucky Bluegrass Spread? (How Fast?)

Kentucky bluegrass is the fastest spreading cool season grass. The grass is perennial, meaning it grows yearly from the same roots. KBG spreads via rhizomes. So, how fast does Kentucky blue grass spread?

Kentucky bluegrass is the fastest spreading cool season grass. It spreads through rhizomes to form a thick dense turf within a short period of time. To encourage it to spread faster, you need to water, fertilize and mow appropriately. 

Does Kentucky Bluegrass Spread?

Kentucky bluegrass is the fastest spreading cool season grass. When given the right growing conditions, one seed can grow and spread to cover one square foot in one growing season. 

The grass seeds take longer to germinate as they can take up to 14 days before the first seed shoot compared to other grasses, which take 5 – 10 days. However, once the seeds germinate, it takes a shorter time to spread and will overtake other grasses.

Kentucky bluegrass rhizomes spread in a network forming a thick turf. Its ability to spread fast and make a thick sod makes the grass ideal for high-traffic areas because not only does it have high traffic tolerance, but it has a high recovery rate.

Kentucky bluegrass is one of the grasses that stay green in winter. It is suitable for home lawns, golf courses, and sports fields.

How fast does Kentucky Bluegrass Spread?

Kentucky bluegrass spreads quite fast. One single seed can grow to cover one square foot, while established grass can grow to cover bare patches of up to 24 inches in one growing season. 

Even so, it is important to note that the grass will only spread if adequately cared for. For example, the grass does not have deep roots and therefore cannot tolerate drought.

Failure to water the grass, especially during drought, will cause the grass to dry. Other important ways to make KBG spread faster are to mow it appropriately and fertilize it. With regular lawn maintenance, the grass will spread on its own. 

How to make Kentucky Bluegrass Spread Faster

Kentucky bluegrass spreads through rhizomes, and therefore the health of the roots will determine how fast the grass spreads. Having healthy roots will depend on how well you prepare the ground before seeding to how you take care of the lawn after the grass establishes.

Although the grass will still spread on its own, you can do the following to encourage it to spread faster.

1. Overseeding

The seeds you plant are as important as the grass you will get, and therefore, it is important to plant high-quality seeds. Kentucky bluegrass has over a hundred cultivars that come in different colors and other characteristics such as shade tolerance.

Therefore when buying seeds, you should buy the cultivar that will grow best on your lawn. You can visit a nearby extension to get knowledge on a suitable cultivator to use in your region.

Although Kentucky bluegrass spreads on its own, it is important to overseed to ensure as many seeds sprout. If only a few seeds germinate, it will take longer for the grass to fill the lawn than when many seeds germinate. An over-seeded lawn also forms a thick mat that easily chokes out weeds.

To ensure many Kentucky bluegrass seeds germinate, you should do the following.

  • Test the soil – Test it to ensure it is within the ideal pH range for Kentucky bluegrass of 6 – 7. If the soil pH is above the recommended range, you can add aluminum sulfate or sulfur to lower it.
  • To raise the pH, you can use pulverized lime or granulated lime.
  • If the pH is ideal, till the ground to a depth of at least 3 inches. Rake to remove vegetation and smoothen the yard. 
  • Add nutrients – You can use compost and fertilizer and mix them up with the soil.
  • Spread the grass seeds – You can use a lawn spreader to spread the seeds effectively. 
  • Cover the seeds with soil – You can use a rake or lawn roller to cover the seeds with soil to protect them from being blown or washed away.
  • Water the seeds until the grass germinates.

Kentucky bluegrass is not shaded tolerant and should not be planted on a lawn with trees.

2. Watering

Water is essential for any grass to thrive. Kentucky bluegrass requires one inch of water per week during the cool season. However, during warm weather above 75°F, you should increase the water to 2 inches per week. 

Kentucky bluegrass has very shallow roots and, therefore, is not drought-tolerant. Water the lawn appropriately to help the grass spread faster. 

3. Fertilizing

Feeding your grass sufficient nutrients will help it spread faster. You should fertilize the lawn before planting grass seeds to help them sprout strong. During the growing season, you should also feed the grass 2-3 times to maximize spread because strong roots spread faster.

However, do not over-fertilize because you will kill useful microorganisms in the soil. Without these microbes, there will be thatch buildup that will prevent seeds from germinating and cause the lawn to thin.

4. Aeration

Aeration will help nutrients, water, and air to reach the roots and enable them to spread further and faster. When the soil is compacted, the roots will have difficulties spreading because the soil is too hard.

There will also be insufficient water, air, and nutrients as they won’t be able to penetrate the compacted soil. When you do aeration, the roots will spread and sprout into the grass shoots which will fill up the lawn quickly. Aeration should be done during early fall.

5. Mowing

Kentucky bluegrass should be mowed to a height of 2.5 – 3 inches during spring and fall and 3-4 inches during summer. Mowing too low will encourage the growth of weeds while mowing high encourages deep rooting and helps with heat and drought resistance. However, never mow more than ⅓ at a time.


Although it takes longer for Kentucky bluegrass seeds to germinate, once established, the grass will spread fast to fill up the lawn. To encourage the grass to spread faster, you should overseed, water, fertilize, aerate and mow appropriately.


  1. Pennsylvania State University: Kentucky Bluegrass
  2. Umass Extension: SELECTION OF GRASSES

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