Overseeding Zoysia with Fescue [Good or Bad Idea?]

You will have poor results if you attempt to overseed an existing Zoysia lawn with Fescue. Zoysia grass grows thickly and resists all attempts at overseeding. This means that if you spread Fescue seed on your Zoysia, you will get very few Fescue sprouts. Additionally, because Zoysia grows so fast and vigorously, Fescue will not crowd out Zoysia. If you want to transition your lawn from Zoysia to Fescue, you’ll have to kill the existing Zoysia grass and seed Fescue on bare soil.

Can You Mix Fescue and Zoysia?

Fescue and Zoysia grass mix poorly. Fescue is a bunch-forming, cool-season grass that prefers shady areas. Zoysia grows low to the ground, spreads through rhizomes and runners, and chokes out other grasses in sunny areas. Because Zoysia is so aggressive, it is prone to overrunning any Fescue in your yard. If any clumps of Fescue remain, they will likely be confined to shaded areas. This leads to an uneven, patchy appearance in your lawn, rather than a true blend of grasses.

• Fescue seed spread over Zoysia grass sprouts at a very low rate.
• Fescue will likely be choked out by Zoysia.
• If Fescue survives, it will be contained to the shady regions of your lawn.
• Fescue is a bunch-forming grass that spreads slowly, while Zoysia spreads aggressively.
• Fescue and Zoysia require different mowing heights.

Fescue and Zoysia care also differ wildly. Zoysia grows best when mowed around 2 inches (5 cm) tall. Meanwhile, Fescue should be mowed at a height of 3 inches (7.5 cm) or taller. If you cut Fescue too short, it will die. If you mow Zoysia too long, it will struggle and grow thinly. The two types of grass coexist poorly together, so mixing them is not advised.

Does Fescue Kill Zoysia?

Fescue is extremely unlikely to choke out or kill Zoysia grass. In fact, the opposite is much more likely. Warm-season grasses, like Zoysia, experience a massive growth spurt in summer. At this time, Fescue grows slowly. If you overseed your Zoysia lawn with Fescue, the few Fescue sprouts that come up are likely to get choked out by Zoysia during summer.

What Grass Can You Overseed Zoysia With?

Zoysia is a poor candidate for overseeding simply because it grows so thickly and develops such complex root systems. Any grass seed you spread over your Zoysia lawn will struggle to reach the soil level in order to germinate. Even if you scalp your Zoysia lawn, you’ll experience poor results overseeding it. The dense root systems of Zoysia make it hard for other grasses to get a toehold and develop roots of their own.

• Zoysia does not respond well to overseeding with any grass variety.
• The dense blade and root growth of Zoysia prevents new grass seed from growing.
• Other warm-season grasses allow for overseeding, Zoysia does not.

Some warm-season grass varieties, such as Bermuda grass, can be overseeded with Annual Ryegrass in fall to provide a green lawn in winter. This is possible because Bermuda grass grows much thinner than Zoysia, making this overseeding possible. When dealing with a Zoysia lawn, overseeding efforts typically result in wasted money because the grass seed you spread won’t sprout.

How to Transition from Zoysia to a Fescue Lawn

If you want to change your Zoysia lawn over to Fescue, overseeding isn’t the answer. Instead, you will need to kill your existing Zoysia lawn with several non-selective herbicide treatments from May through July. Then, scalp the dead yard, till the soil, and seed with Fescue in September.

• Kill existing Zoysia by spraying this herbicide on your lawn once every 10–14 days from May 1 through July 15.
• Scalp the lawn by mowing at 1-inch height.
• Use a rototiller to break up the soil and destroy Zoysia root materials.
• In the first week of September, overseed with Fescue.
• Cutting and removing Zoysia with a sod cutter won’t eliminate Zoysia from your lawn, so herbicides are a necessity.

Due to the fact that Zoysia produces such deep and extensive roots, systemic herbicides must be sprayed on your Zoysia lawn to kill it down to the root. Only then can it be replaced. Simply cutting off the top portion of the lawn with a sod cutter won’t remove your Zoysia grass. It will regrow from the roots. If you don’t spray with herbicide first, Zoysia will come back, re-invading your new Fescue lawn shortly after seeding.

Which is Better: Zoysia or Fescue?

When it comes to whether Zoysia or Fescue is right for you, it’s all about location. Zoysia thrives in warm regions with long summers and mild winters. Although it is brown and dormant in winter, Zoysia remains green throughout the hottest part of the year. Fescue is the direct opposite. It goes dormant in summer if temperatures reach 90℉ (32℃). However, it stays green later into winter than Zoysia. Choose the best grass for you based on your climate.

• Zoysia performs better in warmer regions with long summers and short winters.
• Fescue grows best where summers are mild. It can withstand lower temperatures.
• In the transition zone, both Fescue and Zoysia can be planted effectively.

In the middle portion of the United States, known as the Transition Zone, both warm-season and cool-season grasses can be grown. However, local temperatures vary. If you’re tired of having a brown lawn in the hottest part of summer, grow Zoysia instead of Fescue. If your Zoysia is dormant most of the year due to cold fall, winter, or spring temperatures, replace it with Fescue.

Can You Crowd out Zoysia Grass?

Zoysia grass resists being crowded out. You will have little to no luck attempting to crowd out Zoysia by overseeding with Fescue or any other grass. Zoysia develops a very dense carpet of blades that kill off invading grasses. Additionally, Zoysia spreads relatively quickly through runners and roots, meaning it’s likely to be the aggressor and choke out other plants, rather than vice-versa.

Can You Overseed Zoysia Grass With Tall Fescue?

Overseeding Zoysia with Tall Fescue is a waste of money. Zoysia grows too thick and has too dense of a root system for the Fescue seed to sprout or take root. You will get little to no Fescue sprouts from overseeding a Zoysia lawn, meaning your expenses on Fescue seed will go to waste. If you’re determined to replace a Zoysia lawn with Fescue, you will have to use a systemic herbicide to kill all the Zoysia over the course of an entire summer. Then, in fall, you can seed Fescue on bare ground.