In order to mix Kentucky Bluegrass and Tall Fescue in your yard, purchase a seed mix that contains 10% Kentucky Bluegrass and 90% Tall Fescue. Once you have your seed, spread it according to these rules:
- 2–4 pounds of seed per 1,000 square feet: when overseeding thick, established lawns.
- 4–8 pounds of seed per 1,000 square feet: When overseeding patchy or struggling lawns.
- 8-12 pounds of seed per 1,000 square feet: When seeding bare ground.
The best time to seed your lawn with Fescue and Kentucky Bluegrass is in late summer and early fall, typically August through September. Both kinds of grass perform best in cool-season grass zones and transitional zones.
Why Blend Fescue and Kentucky Bluegrass in Your Yard?
Kentucky Bluegrass and Tall Fescue are an ideal mix for lawns in areas with cold winters. The reasons the two types of grass work so well together are:
- Fescue is a low-maintenance cool-season grass that grows well with little fertilizer and low amounts of water.
- Kentucky Bluegrass is a higher maintenance cool-season grass that repairs from damaged areas of the lawn quickly and has an incredible appearance.
- A blend of grasses increases resilience (diseases that attack one grass may not attack another).
By mixing Kentucky Bluegrass with Tall Fescue, you get the benefits of both and reduce the negatives of each. Your lawn will thrive with moderate maintenance and watering, repair itself quickly, and remain attractive through summer heat and brisk fall temperatures. To better understand these grasses and why we blend them, let’s take a closer look at each type.
Fescue Pros and Cons
Fescue is a great filler grass for yards because it thrives with as little as 4 hours of sunlight per day, withstands drought, and holds up to use.
- Grows well in shade or sun.
- Tolerates drought and heat well.
- Has low fertilizer needs (1 pound of nitrogen per 1,000 square feet annually).
- Has low water needs (1–1.5 inches per week).
- Holds up well to traffic and use.
- Is disease-resistant.
- Requires frequent mowing.
- Is prone to growing in unattractive “clumps.”
- Enters dormancy early in fall/winter.
- Does not repair damaged or patchy areas quickly.
An unattended fescue yard can take on an overgrown appearance in just a couple of weeks. Not only that, but the grass may grow in bunches, leading to an uneven lawn. If your yard is seeded with only fescue, it’s likely to take on a ragged, patchy appearance.
Kentucky Bluegrass Pros and Cons
Kentucky Bluegrass is a beautiful species that spreads and reclaims damaged portions of the yard thanks to its underground rhizomes. It resists cold and remains green much later into the year than fescue.
- Remains green into fall and early winter.
- Reclaims damaged and patchy areas.
- Blades grow more slowly than Fescue, reducing mowing frequency.
- Grows to create an even, attractive lawn.
- Does not tolerate shade well.
- Struggles in heat and drought.
- Requires more water than fescue (2 inches per week).
- Has high fertilizer needs (3–6 pounds of fertilizer per 1,000 square feet).
Because Kentucky Bluegrass has relatively high fertilizer and watering needs, it’s considered a greedy grass. Also, it may go dormant in summer if temperatures rise too high. By mixing Kentucky Bluegrass with Tall Fescue, your yard will have much lower watering and fertilizing needs, and remain green in peak summer temperatures.
Where Will Kentucky Bluegrass and Tall Fescue Blends Grow?
Both Kentucky Bluegrass and Tall Fescue are cool-season grasses. This means they will grow in the northern half of the United States, from coast to coast. They will also grow in what are known as “Transitional Zones,” where both warm and cool-season grasses can thrive.
- The northern half of the United States, as well as Transitional Zones, as shown on this map.
- All regions of Canada.
- Great Britain and Ireland.
These cool-season grasses will also grow well in Canada, as well as Great Britain and Ireland, where the climate is ideal for cool-season grasses.
How to Choose the Right Fescue and Kentucky Bluegrass Blend
The best seed blend for your yard is 10% Bluegrass and 90% Fescues, by weight. Because Bluegrass seeds are smaller and lighter than Fescue seeds, you’ll actually get close to a 50/50 mix in seed quantity. Some mixes contain more than one cultivar of Bluegrass or Fescue, but as long as they add up to 10/90, you’re on the right track.
- 10% Kentucky Bluegrass and 90% Tall Fescue seed by weight.
- Avoid K-31 Tall Fescue. It’s prone to growing in clumps.
- Consult with a regional seller to determine what Kentucky Bluegrass and Tall Fescue varieties are best for your lawn.
Discuss the best grass cultivars for your region with a reputable seller. Some breeds of Bluegrass and Fescue are developed for more heat or drought resistance, which you may need in a warmer area. Some other grass cultivars may perform better in cold regions. Make sure your seed mix is tailored to your area.
What Month is Best to Seed Your Bluegrass and Fescue Mix?
Plan to seed your Bluegrass and Fescue mix in late-August through September. Cool-season grasses grow best in fall, so seeding at this time will result in the greatest seed germination rate. By seeding 45 days before the first average fall frost, you allow the grass to establish itself before winter.
- Late August through September.
- 45–60 days before first average fall frost.
Not only will you get an impressive green-up in fall from this method, when spring arrives your new grass will receive a second boost. It will be fully mature and established lawn by summer.
Will Kentucky Bluegrass Choke Out Fescue?
Kentucky Bluegrass and Tall Fescues coexist well together, so it’s unlikely for one to choke out the other. Fescues will thrive in the shady portions of your yard, while your bluegrass will work to fill in bare spots where grass has been damaged.
- The two kinds of grass will coexist. Kentucky Bluegrass is unlikely to choke out Fescue.
- Fescues grow better in shade and will grow in hotter temperatures than Bluegrass.
- Bluegrass fills in bare spots and grows more actively in cooler temperatures.
Because Fescues and Bluegrass thrive in slightly different conditions and times of the year, it’s unlikely for one to wipe out the other. Instead, they’ll balance each other, each one making gains while the other’s growth slows.
Is Tall Fescue or Kentucky Bluegrass Better?
Both Tall Fescue and Kentucky Bluegrass have their pros and cons. Fescue is lower maintenance but results in a clumpy, ragged lawn. Kentucky Bluegrass requires more water and fertilizer, but it fills in bare spots left by clumpy grass. Because of this, the best solution is a blend of the two species in your lawn.
By purchasing a Kentucky Bluegrass and Tall Fescue blend, you will get the benefits of both types of grass and reduce the drawbacks of maintenance and disease. The result is a beautiful, resilient lawn with long periods of green growth.