Plant Turf Seed or Control Weeds First?

A common question this time of year is whether to plant turf seed now and control weeds later OR to instead control the weeds now and then seed later. Here are my thoughts.

Cool-season turf seed mixture.

Option 1 for areas with mainly broadleaf weeds and a few annual grasses: Plant now and control weeds later.
The optimum time to control perennial broadleaves and germinating winter annual broadleaves is in October. As such, seeding in late August and early September should allow enough time for seeds to germinate, grow, and be mown twice (assuming you irrigate and fertilize these newly seeded areas) prior to an October herbicide application. You can delay the herbicide application until late October and early November if you get a late start on seeding or if your seedlings are slow to establish (like Kentucky bluegrass). Most broadleaf herbicide labels suggests delaying application until newly seeded areas have been mown twice. Some herbicide labels allow a shorter interval between seeding and an application. These shorter interval herbicides include Quicksilver, SquareOne, and Drive (shorter interval tall fescue compared to perennial ryegrass and Kentucky bluegrass).

Typical language about postemergence herbicide application delays after seeding turf.

Drive XLR8 label instructions regarding application timing and seed and seedling emergence.

Option 2 for areas where you have lots of weed competition: Spray weeds now and seed tomorrow.
When there is a lot of crabgrass or broadleaf weed cover, then you would likely benefit from spraying the weeds now and seeding afterwards. Tenacity, Pylex, and SquareOne, and Drive are among the herbicides that can be applied today and allow seeding as soon as tomorrow (after the herbicide has had a chance to translocate in the target weed). Once the turf germinates, then follow the guidelines in option 1 above to provide follow-up weed control if needed.

SquareOne application instructions allowing seeding one day following the herbicide application.

Option 3 for areas perennial grassy weed competition: Spray weeds now and seed later.
When there are a lot of perennial grassy weeds such as quackgrass, fountain grass, etc., then your best bet to remove these perennial grasses before you seed as there are few herbicide options afterwards.
Best results with a non-selective herbicide like glyphosate are seen on perennial grassy weeds when multiple applications are made. Ideally, you would have started this process several weeks ago. Why? It is not uncommon for the weed to regrow from stolons or rhizomes (if a spreading grass) a few weeks after the first glyphosate application. One must allow the weed to regrow (wait at least three weeks) before the next application. At least two applications are recommended, but three or more may be needed. One must realize that the area will be dead and unsightly for a number of weeks or months if optimum control is desired.

Starting this process now, means that you won’t be able to seed until after the optimum seeding window of August 15 to September 15. If you are still committed to renovating this year, another seeding option is to seed in December through March as a dormant seeding after you have finished killing your perennial grassy weeds. Learn more about dormant seeding by clicking here.

If there are only a small number of patches, spot applications can be made with glyphosate. Reseeding can take place a day or two following final herbicide application. Once the area has been infested with a large number of patches, killing the entire area will be most effective with multiple applications of glyphosate. Renovation can begin five to seven days following final glyphosate application. Refer to AY-13, “Lawn Improvement Programs” for information on reestablishment.

One caveat to the above, Option 3 recommendation, is that we have a few selective herbicides for perennial grassy weed control that might be options for use during turf renovation.

Table 1. Non-selective and selective herbicide options for controlling perennial grassy weeds in cool-season turf.

Weed in cool-season turf	Non-selective herbicide option	Selective herbicide option
Bermudagrass	glyphosate	Pylex (topramezone), Acclaim Extra (fenoxaprop)
Creeping bentgrass	glyphosate	Tenacity (mesotrione)
Dallisgrass	glyphosate	No effective selective control
Field paspalum	glyphosate	No effective selective control
Fountain grass	glyphosate	Drive (quinclorac) and other quinclorac containing herbicides
Nimblewill	glyphosate	Tenacity (mesotrione), Pylex (topramezone)
Orchardgrass	glyphosate	No effective selective control
Quackgrass	glyphosate	No effective selective control
Rough bluegrass	glyphosate	Velocity (bispyribac-sodium) for golf courses and sod farms.
Tall fescue	glyphosate	No effective selective control, formerly Corsair (chlorsulfuron)
Windmillgrass	glyphosate	Tenacity (mesotrione)
Zoysiagrass	glyphosate	Pylex (topramezone)(based on preliminary results following labeled instructions for bermudagrass control)

With any of these options, it is especially important to read the herbicide label and understand the application restrictions both before and after seeding and other application instructions (such as adjuvant and timing recommendations) so that you can maximize weed control and maximize turfgrass establishment.

For more information on weed control, search this blog and check out our Turfgrass Weed Control for Professionals Publication.

Aaron Patton, Turfgrass Extension Specialist

Fescue. You mean there’s more than one kind?

Typical conversation about fescues.

Bill: What kind of grass do you have?
Bob: Fescue.
Bill: What kind of fescue?
Bob: You mean there’s more than one kind?
Bill: Yes.

As I travel around the region and give presentations or respond to email and phone questions, it is very common for me to enter into a dialogue with a person about planting, maintaining, controlling, etc. some kind of fescue. Usually in my interactions with people, they are unaware that there are many different kinds of fescues.

Festuca is the genus (first word in scientific name) for fescue species. Hence, Festuca’s are name Fescue. However, recently tall and meadow fescue were reclassified by scientists into the genus Schedonorus (see table below) although they still retain their same common name of fescue. Tall fescue and meadow fescue are similar with meadow fescue being used sparingly for overseeding in warm-season turf or as a forage grass and tall fescue commonly being used in lawns, roadsides and pastures. The remaining fescues including slender creeping red fescue, strong creeping red fescue, Chewings fescue, sheep fescue, blue fescue, and hard fescue are often grouped together and called “fine fescues” because of their narrow (fine) leaves. Another reason for grouping them all together is because they are difficult to distinguish from one another. Blue fescue is another fine fescue species used as an ornamental landscape grass.

Below is a breakdown of the common (and a few not so common) fescues used in turf (and ornamentals) and a short description of each.

Table 1. Description of the common and uncommon fescues used in turf (and ornamentals).

Common name	Species	Comments
Slender creeping red fescue	Festuca rubra ssp. littoralis	Similar to strong creeping red fescue but with shorter, more slender rhizomes. Both slender and strong creeping red fescue tolerate some close mowing.
Strong creeping red fescue	Festuca rubra ssp. rubra	Strong creeping red fescue has more rhizome growth (spreading ability) than slender creeping red fescue. Strong creeping red fescue is a common ingredient in “Sun & Shade” mixes because of its good shade tolerance and its suitability in seed mixtures.
Chewings fescue	Festuca rubra spp. fallax	Named after George Chewings. Excellent shade tolerance and turf density, this fine fescue is similar to creeping red fescue but it lacks rhizomes.
Tall fescue	Schedonorus arundinaceus (Schreb.) Dumort. (also = Lolium arundinaceum (Schreb.) S.J. Darbyshire; formerly = Festuca arundinacea Schreb.)	Improvements in tall fescue have transformed this grass from a forage type grass to many improved turf-type cultivars. Today, both "forage" and "turf-type" tall fescue are used. Kentucky-31 (KY-31) is a forage type and not a lawn type. Known for its ability to maintain green color during moderate droughts due to its deep root system, tall fescue is more commonly used today on lawns than in the past.
Sheep fescue	Festuca ovina	Excellent drought tolerance. This fine fescue with fair turf density does not tolerate close mowing. It is often used in unmown, “native” areas of golf courses.
Blue fescue	Festuca glauca	Ornamental grass. Common variety is ‘Elijah blue’
Meadow fescue	Schedonorus pratensis (Huds.) P. Beauv. (formerly Festuca pratensis Huds.)	Similar in appearance to tall fescue. Little current use in high value turf.
Hard fescue	Festuca brevipilla	Excellent shade tolerance, this fine fescue does not tolerate close mowing. It is often used in unmown, “native” areas of golf courses.
Red fescue	Festuca rubra	Today, red fescue is classified into two groups: 1) Slender creeping red fescue or 2) Strong creeping red fescue. However, some seed labels may still just say, red fescue.

Figure 1. Unmown, fine-fescue used on a golf course. These areas are often described as no-mow, native areas, or environmentally sensitive areas to the golfers.

Figure 2. Chewings fescue. Notice the fine leaf texture (narrow leaf width) compared to tall fescue below.

Figure 3. Tall fescue (turf-type).

Aaron Patton, Turfgrass Extension Specialist

New Lawn Recovery Guide

The Purdue Turf Program has put out a new publication to help homeowners and professional answer some of the questions asked about drought stress.

Lawns and the Summer 2012 Drought/Heat Crisis: Now What? | PDF

Imprelis® Update: Stop Sale, Use, or Removal Order. Q&A

The following post provides an update on Imprelis® herbicide in a Question and Answer format.

Q: What action has the Office of Indiana State Chemist (OISC) recently taken concerning Imprelis®?



A: The OISC issued a stop sale, use, or removal order (SSURO) on August 1, 2011 for the herbicide Imprelis®. The OISC has reason to believe that DuPont Imprelis® Herbicide, EPA Reg. #352-793, when used as directed or in accordance with commonly recognized practice, has caused injury to non-target vegetation, except weeds to which it has been applied, and is therefore MISBRANDED. Therefore, the OISC is hereby issuing a STOP SALE, USE OR REMOVAL ORDER (SSURO) to DuPont Professional Products. This SSURO requires DuPont Professional Products to cease all sale, distribution and use of DuPont Imprelis® Herbicide, EPA Reg. #352-793, in the State of Indiana, effective immediately. This SSURO pertains to any and all quantities and sizes of DuPont Imprelis® Herbicide, EPA Reg. #352-793, within the ownership, control or custody of DuPont Professional Products wherever located. In addition, DuPont Professional Products shall not commence any movement of this product from any present location without prior written approval from the OISC. Any person violating the terms or provisions of this SSURO shall be subject to civil or criminal penalties as set forth in IC 15-16-4.

Q: What is the stance of the United States Environmental Protection Agency (EPA) concerning Imprelis®?



A: On August 11, The EPA issued a SSURO for the herbicide Imprelis®. Previously, the EPA issued a letter to DuPont on August 3, 2011 stating two concerns. First, that the EPA is considering issuing an SSURO (described above). Second, the EPA is concerned about the lack of information that is being provided by DuPont to the public concerning the efficacy of Imprelis®. The EPA “strongly encourages DuPont to reconsider” providing information related to the phytotoxicity studies related to effects on trees. More information about Imprelis, including EPA registration of the herbicide, is available at: http://www.epa.gov/pesticides/regulating/imprelis.html

Q: What action has DuPont taken to comply with the OISC?



A: DuPont is implementing a voluntary suspension of sale of Imprelis® herbicide. More information is available at http://www.imprelis-facts.com/ and at (866) 796-4783.

Q: Can I still apply Imprelis® herbicide in Indiana if I have some leftover?



A: No. The SSURO issued by OISC does not allow the continued use of existing Imprelis® herbicide.







Q: What do I do if I have leftover Imprelis® herbicide?



A: DuPont has stated that they will initiate a product return and refund program in mid-August 2011. More details about this will be shared when they become available.

Q: Where can I get more information from DuPont about Imprelis®?



A: Website (http://www.imprelis-facts.com/) and hotline ((866) 796-4783) are available.

Q: Where can I get more information from Purdue and the OISC about Imprelis®?



A: Read news alerts from the Office of Indiana State Chemist at http://www.isco.purdue.edu/, read more from the Purdue University Turf Program at http://www.agry.purdue.edu/turf/, and received updates from the Plant and Pest Diagnostic Laboratory at http://www.ppdl.purdue.edu/ppdl/.

Read past documents created on July 22, 2011



A Homeowner’s Guide to Suspected Imprelis® Herbicide Injury in the Landscape



A Turf Professional’s Guide to Suspected Imprelis® Herbicide Injury in the Landscape

Aaron Patton, Turfgrass Extension Specialist

Turf: Dead or Alive?

Many areas in Indiana have received recent rains to their lawns. Some lawns have greened-up and others are still brown leaving many wondering whether their lawns are dead or alive. Below are some images that illustrate the process of determining whether or not your lawn is dead or alive.

Step 1. In an area of suspected dead turf (brown areas), pull at the brown (dead) leaf blades.

Step 2. After pulling up some of the dead leaf blades, examine the ground closely and look for signs of new growth. All new turf growth comes from the crown of the plant (turf) and these crowns are located at or near the soil surface.

Step 3. If you find new turf emerging in these dead areas then that is good news that your turf will recover from drought and heat injury. If not, wait a few more weeks and reexamine these areas.

Step 4. If no new growth is occurring in areas you might need to reseed these spots. For lawns with bunch-type grasses such as tall fescue and perennial ryegrass, reseed dead spots larger than 3 inches in diameter. For Kentucky bluegrass lawns, reseed dead spots larger than 6 inches in diameter (about the size of your hand, or at least mine). Since Kentucky bluegrass has rhizomes (underground stems) it has a greater recuperative capacity than bunch-type grasses. The photo below shows a bare area between clumps of perennial ryegrass.



Aaron Patton, Turfgrass Extension Specialist

Certainty Turf Herbicide Label Changes

Monsanto recently updated the Certainty® Turf Herbicide label 2015-1 on packaged goods. These changes are effective on product packaged and shipped after May 2011. All cool season turfgrass uses for Certainty have been removed from the 2015-1 label. The product can still be used on warm-season turf. The label change also adds nursery and landscape recommendations for preplant, directed and over-the-top applications in ornamentals and groundcovers.

Q: What does this mean?



A: Product packaged before these changes can continue to be used according to label directions in cool season turf, but any Certainty® purchased in the future will be labeled only for use in warm-season turf like bermudagrass and zoysiagrass.

Q: Certainty® worked well on yellow nutsedge in Kentucky bluegrass, what should I use now?



A: Many herbicide options are available for sedge control in cool-season turf including bentazon (Basagran), LescoGran), halosulfuron (SedgeHammer, ProSedge, others), mesotrione (Tenacity), sulfentrazone (Dismiss), and sulfentrazone containing herbicides (Echelon, Q4 Plus, Solitare, Surge,TZONE).

Q: Certainty® was labeled for rough bluegrass control in Kentucky bluegrass and creeping bentgrass, what should I use now?



A: Velocity is the only other turf herbicide labeled for rough bluegrass control, but it is only labeled for sod and golf course use. Rough bluegrass control in residential and commercial lawns will now need to be controlled with non-selective applications of glyphosate.

Q: Certainty® was labeled for suppression and partial control of quackgrass. Are there alternatives for selective quackgrass control in cool-season turf?



A: No. Certainty® was the only herbicide labeled for selective control of quackgrass in cool-season turf (primarily Kentucky bluegrass). Quackgrass will now need to be controlled with non-selective applications of glyphosate.

Aaron Patton, Turfgrass Extension Specialist

Start Seeding Cool-Season Turf Now

The best time to seed a cool-season lawn is in the late summer to early fall. Adequate soil moisture, warm soil, and limited weed pressure allow for excellent seedling growth. Normally, we recommend seeding between August 15 and September 15 as the optimum seeding window. However, due to our cool summer and a relatively cool forecast for August, we are recommending that you can start seeding anytime now and there is no need to wait until mid-August.

It is critical to seed as early as possible within this window. Even when seeding within this window, waiting one week later to seed may mean the turf will take 2 more weeks to mature as germination and subsequent growth slows later in the fall as temperatures cool. Additionally, annual bluegrass and other winter annual weeds will be more problematic with fall seeding dates than late summer seeding dates.

Seeding early (later summer) allows the turf to maximize its establishment and rooting prior to the next summer's heat and drought.

For more information about establishment, see:

• Establishing Lawn Areas From Seed (AY-3-W) | PDF

• Seeding a Turf Area in the Spring (AY-20-W) | PDF

• Purchasing Quality Grass Seed for Your Lawn (AY-25-W) | PDF

• Establishing a Lawn from Sod (AY-28-W) | PDF

Aaron Patton, Turfgrass Extension Specialist