Tall Fescue Management – How To Control Tall Fescue Weeds


By: Mary H. Dyer, Credentialed Garden Writer

Tall fescue in the lawn is a significant pest. In fact, saying that controlling tall fescue is difficult is an understatement. The thick root masses are nearly impossible to pull and mowing only encourages growth of this aggressive plant. How to get rid of tall fescue in your lawn? Read on for tips and suggestions.

About Tall Fescue Weeds

Tall fescue (Festuca arundinacea) was introduced to North America by European settlers who planted it to provide hardy, nutritious forage for livestock. Since the plant remains green even in dry conditions, it was widely planted in the 1990’s to replace thirsty Kentucky bluegrass in drought-ravaged regions.

Tall fescue weeds are opportunistic, popping up in disturbed habitats, including along roadsides and railroad tracks, in pastures and abandoned fields, and sometimes along streambanks. It tolerates a wide range of soils and moisture conditions.

Although it was initially planted with only the best intentions in mind, tall fescue has naturalized into many parks and other public areas in the United States and southern Canada, where it competes with native species. It is considered an invasive species in many regions.

How to Get Rid of Tall Fescue

Tall fescue weeds emerge in early spring and reach maturity by late summer. The clumps of wide -eaved grass may form new growth in autumn and will remain green all winter in mild climates. Although pulling the weed is next to impossible, you may be able to dig seedlings and isolated clumps early in the season.

Otherwise, the only recourse for fall fescue management may be to spot treat weeds with a product containing glyphosate. You can spray anytime the plants are growing, although some sources recommend spraying in spring or late fall. Herbicides aren’t effective when tall fescue weeds are dormant.

Always follow manufacturer recommendations and remember that the herbicide may kill other plants as well. Wear chemical-resistant gloves and protective goggles, a long-sleeved shirt, long pants, and closed toe shoes with socks.

Check with your local cooperative extension office for more information on tall fescue management and about the specifics of using glyphosate in your particular situation.

Note: Chemical control should only be used as a last resort, as organic approaches are safer and more environmentally friendly.

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June Through August

Mowing
Mow to 3 1 ⁄2 inches and mow before the grass gets taller than 5 inches.

Fertilization
DO NOT fertilize tall fescue at this time.

Watering
Either water as needed to prevent drought stress or allow the lawn to go dormant. Dormant lawns must be watered once every 3 weeks during a drought.

Disease Control
Tall fescue is highly susceptible to brown (large) patch disease, which appears as irregularly shaped patches of dead or dying turf. Brown patch likes high humidity and temperatures above 85°F. It becomes extremely severe during prolonged, overcast wet weather with evening air temperatures above 68°F. and daytime temperatures in the mid- to upper 80s. Do not apply nitrogen fertilizer when the disease is active, keep the mowing height above 3 inches, and water between 2 and 8 am. Apply fungicide during severe brown patch outbreaks. (See Diseases of Cool-Season Grasses, AG-361.)

Weed Control
DO NOT use herbicides at this time.

Insect Control
Check for and control white grubs in July and August.

Aeration
DO NOT aerate tall fescue lawns at this time.

Renovation
Western region only! Overseed thin, bare areas as weather cools (August 15 to September 1). Use a blend of “turf-type” tall fescue cultivars at 6 pounds of seed per 1,000 square feet, and apply a starter-type (high phosphorous) fertilizer. Keep the seedbed moist with light watering several times per day. Do not let the seedlings dry out.


Killing Fescue Effectively and Economically in Food Plots

By Kent Kammermeyer, Senior Wildlife Biologist

Our wildlife managers have been fighting fescue in deer food plots for years. Until recently, we have been gradually losing the battle by employing a system of plowing and planting shade producing crops that temporarily prevent fescue from re-invading. Encroachment from plot edges and small gaps in our shade crop (corn or grain sorghum) has always seemed to eventually thwart our efforts. A publication entitled "Handling the Fescue Problem" by Jeff Sole and Pat Keyser put us on the right track toward permanently getting rid of fescue in our deer food plots.

With all spraying, timing of spraying is critical. Fescue should be sprayed when it is actively growing (April to mid-May and/or September to mid-October) and is about 8-12" tall. You can also mow in May or August, wait 2-3 weeks for re-growth and spray. Dry spells that slow fescue growth should be avoided. Here is our formula for an effective kill of fescue:

2 quarts/acre of 41% glyphosate + surfactant 1 pt/acre additional non-ionic surfactant 2 pt/acre ammonium sulfate (Quest) Apply 25-40 gal/acre solution(25 is better).

Follow all label directions for mixing. We have tried mixing a blue die called Turf-Mark in the tank at a high rate (over a qt/acre) to mark our spray path and keep from missing streaks and over-spraying. It did not work the color was barely detectable even upon close inspection. Wait l to 2 weeks and spray remaining green spots if needed, then plant. In spring, plant a tall food plant such as grain sorghum, corn, dove proso millet or sunflowers. A no-till drill works great for these. The object is to get a dense shade on top of any fescue seed that might germinate. In fall, you can drill oats or rye and clover mix across the dead fescue. In either case, burning of the dead mulch may be necessary before drilling to allow all drilled seed to contact bare soil.

Plowing the ground a minimum of 2 weeks after the chemical kill is an option but any plowing risks the potential to germinate more weed seeds including any remaining fescue seed. Then another application of glyphosate will be necessary or second choice, plow again. If fescue reinvades at all, it usually is in the form of isolated clumps that can be easily controlled with a backpack sprayer or an ATV mounted sprayer. Small scale mop-up applications may be needed for a year or two.

So far, our program has produced very good results for a reasonable price/acre (all chemicals combined cost us less than $25/acre). By the way, this formula works on a wide variety of weeds including most grasses and broadleaves. When dealing with bermudagrass, use 5 qts/acre glyphosate.


Tall Fescue Lawn Care

As with other cool-season grasses, the best time to plant tall fescue or perform other major lawn tasks is during its peak growth period in fall and spring. Because of its bunch-forming growth, tall fescue lawns rarely need dethatching. However, they benefit from periodic lawn overseeding to keep their density and avoid a clumpy appearance. When damage occurs, Pennington One Step Complete Tall Fescue simplifies repairs. Its combination of premium Smart Seed grass seed and professional-grade fertilizer and mulch repairs bare spots in two weeks or less under proper growing conditions.

Tall fescue's deep roots make good use of soil's moisture and nutrients. Roots benefit from wise lawn water management. Encourage deep growth by watering deeply and infrequently. In the transition zone, ordinary tall fescue varieties require more irrigation than warm-season alternatives, such as Bermudagrass and Zoysia grass, to stay green and healthy during hot summer months. However, water-conserving Pennington Smart Seed grasses require up to 30 percent less water year after year than ordinary grasses. Mow tall fescue lawns as needed to maintain the recommended height of 2 to 3 inches.

Tall fescue adapts to a wide variety of soil types and typically requires less fertilizer than Kentucky bluegrass and other cool-season grasses in similar soil. 3 Soil testing identifies your lawn's soil type, soil pH and nutrient needs so you can fertilizer accordingly. Plant tall fescue in soil with pH between 5.5 and 7.5. 2 For soil pH outside that range, test results may recommend lime or other soil amendments to restore pH balance and keep nutrients available.

With the advent of new varieties and a growing awareness of the benefits of a tall fescue lawn, many lawn owners consider this tough, resilient grass an essential component of their cool-season and transition-zone lawns. Pennington is dedicated to producing the finest grass seed possible and providing premium lawn and garden products and educational resources to assist you in growing a beautiful, healthy lawn — regardless of your grass choice.

Pennington, Smart Seed and One Step complete are registered trademarks of Pennington Seed, Inc.

1. Duble, R.L., “Tall Fescue," Texas A&M Agrilife Extension.

2. Patton, A. and Boyd J., “Choosing a Grass for Arkansas Lawns," University of Arkansas Cooperative Extension.

3. Cook, T., “Tall Fescue,"Oregon State University Department of Horticulture.


Expert Response

Hi JIm - thanks for your response. Sorry for the late reply back from me. Here's some info for you:

  • I have not seen any recent evidence of grubs. I will keep looks throughout and testing different spots in the grass from time to time. I put the Scott down in early June.
  • I've owned the home one year and the person who had it for about 4-5 years before me did some moving around/regrading of soil and then reseeding about 3-4 years ago. So, I think there may some mix of seeds, perhaps.
  • I've fertilized once this year, that's it. Tried to get even coverage and don't see any spotty or streaking coverage. Although, what looks to be KBG (I think) in many areas is green but doesn't seem to be growing in length and in some areas still has seeding on top of many blades.
  • In some areas there are small patches of light colored green grass that is very soft and seems to grown in round patches. Not a lot of that but noticeable.
I've attached three photo that will hopefully help.

Well one thing is certain, you have a blue grass alright but it is the wrong kind. This one is Poa annua which is an invasive weed of the first order. All of the "soft" grass with the seed heads will go along until mid to late august and then brown off (die). The plant does it's best to go to seed as early in the year as possible and then die off leaving you with basically nothing. You can go on Google to find ways to handle or treat it. Just call up Poa annua treatments in lawns and the net should give you a solution.

Thank you for using the Ask an Expert System.

Thanks Jim! Have looked a little on Google about Poa Anna and looks like preemergent is an option.

Do some of the other grasses look like tall fescue? With all these problems is an option to outright kill the large areas of invasive weed grasses and start over?

Jim - thanks for your time and all the great advice!


Watch the video: Weed control for fescue


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