How to Keep Turf Areas Around Sidewalks From Failing

Last year I posted a turf tip on why it is so difficult to manage turf around sidewalks and driveways. I encourage you to read that post (Weed Management Next to Sidewalks and Driveways) as it provides recommendations for weed control, etc. in these areas as well as how to prevent weeds and encourage healthier turf in these spots.

Today's post is a little different. With the pictures below, I want to provide some of my common-sense suggestions on repairing/designing sidewalk areas around turf to help reduce long-term maintenance needs of these areas as well as increasing aesthetics. You might not agree with all of my recommendations, which is fine. However, I hope that you can agree that in most of the below scenarios there is a relatively simple solution (either now or to consider during construction) to reduce long-term maintenance costs.

Aaron Patton, Turfgrass Extension Specialist
Read More

Weed of the month for March 2015 is Tall Fescue

Tall Fescue  

Biology: Tall Fescue (Festuca arundinacea) is perennial grass that can be both desirable as a lawn species when using improved cultivars or undesirable when forage-type (wide-bladed) tall fescue plants a contaminant other primary species in a lawn.

For all of you nerds out there like me, you might be interested in know that there has been much recent debate about the scientific name of tall fescue. While tall fescue has used the above scientific name consistently for over 60 years, it is now being classified by scientists formally as Schedonorus arundinaceus (Schreb.) Dumort. (also = Lolium arundinaceum (Schreb.) S.J. Darbyshire; formerly = Festuca arundinacea Schreb.). I know, very confusing even for me. Remember that there are many grasses called “fescues”. I wrote about this in a previous turf tip that I would encourage you to read (click here).

Identification: Tall fescue is a coarse-textured (wide-bladed), bunch-type grass. Improvements in tall fescue leaf texture have resulted in more fine-bladed varieties/cultivars that have helped to increase the turf quality and use of this drought-tolerant turf in Indiana. We often recommend improved turf-type varieties of tall fescue as the primary species for lawns, but older, wider-bladed, forage-type varieties of tall fescue such as Kentucky 31 (KY-31) still exist, and can be problematic weeds in lawns. This forage-type tall fescue can be easily spotted in lawns in early spring when they green-up faster than Kentucky bluegrass and by its bunch-type growth habit, which results in a clump of turf when present as a weed. Also, forage-type tall fescue can be easily spotted in lawns during drought as tall fescue stays green and actively growing during drought whereas Kentucky bluegrass will often enter a drought-induced summer dormancy.  

Kentucky 31 (KY-31) tall fescue makes a poor lawn.

Improved "turf-type" tall fescue

Sometimes tall fescue blends well into your lawn. Notice tall fescue clump in center of photo.

Weedy, forage tall fescue clumps are easily visible in Kentucky bluegrass turf in early spring.

Tall fescue in bermudagrass turf in the spring during green-up.

Tall fescue (green clumps) in a Kentucky bluegrass turf during a summer drought.

Tall fescue will often lack a ligule or possibly have a short membranous ligule. 

A very short ligule is barely visible.

Auricles are usually short and blunt but some can also be classified as short-clasping meaning that the auricle may wrap-around the stem but may not fully clasp or cross one another. You may also see small hairs protruding from the auricle. 

See the short auricle and small hairs?

The vernation (how the leaf is oriented inside the stem) is rolled on tall fescue and the collar is conspicuous (obvious) and usually wide.

Broad collar is easily visible.

Broad collar is easily visible.

The leaf blade is wide but variable in length with a pointed leaf tip. In some cases you can actually feel little barbs along the leaf margin when you run your fingers from the leaf tip down the leaf blade.One last helpful identification is the prominent veins in tall fescue compared to Kentucky bluegrass (only midrib is clearly visible).

For more on tall fescue identification, see this page in our turfgrass identification tool (click here, requires flash player).

Cultural control: When there are few weedy patches of bunch-type grasses like tall fescue, it is best to cut them out with a shovel or knife. Be sure to cut down a couple of inches into the soil to get all the stems. Refill the holes with soil and seed immediately with the desirable turf species similar to the existing turf.

Biological control: None known.

Chemical control: If the area has a large number of tall fescue plants, chemical control will be more efficient. A nonselective herbicide such as glyphosate (Roundup and others) can be spot-applied. These herbicides will also kill the surrounding desired turf species, so be careful to treat only the clump of tall fescue. Two applications may be needed for complete control and the area should be reseeded 7 to 14-days after the final application. Thoroughly rake the area to be seeded to remove dead plant material and ensure good seed-soil contact. For more information about complete renovation, refer to Turfgrass Renovation (Purdue Extension publication AY-13-W).

Chlorsulfuron (Corsair) was a selective herbicide registered for the control of tall fescue in many turf species. Some quantities of Corsair (labeled for most major turf areas) may still exist but this herbicide is no longer sold. Telar XP and Chlorsulfuron 75DF contain the same ingredient as Corsiar and can be used on turf in industrial sites and roadsides but not in managed turf areas like golf courses, lawns, and athletic fields. Spot apply chlorsulfuron according to label instructions. The tall fescue will slowly thin and die, allowing the desired species to fill in. Reseeding should not be needed if Kentucky bluegrass is present. Chlorsulfuron will kill perennial ryegrass, so do not apply it to perennial ryegrass.

To control tall fescue in warm-season lawns and athletic fields, apply a nonselective herbicide like glyphosate in late winter while bermudagrass is dormant. Alternatively, many sulfonylurea herbicides are labeled for the selective removal of cool-season grasses such as tall fescue from bermudagrass and zoysiagrass.

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

For archives of past weed of the month postings, visit our Weed of the Month Archive.

Aaron Patton, Turfgrass Extension Specialist
Read More

Common Questions About Crabgrass Germination and Preemergence Herbicides Answered

This time of year many have questions about crabgrass germination and control. Below are several previous Purdue turf tips that answer the most commonly asked questions about crabgrass control.
  1. When will crabgrass germinate?
  2. When should I apply my preemergence herbicide (crabgrass preventer)?
  3. Which preemergence herbicide should I use? - Professionals
  4. How to Select a Crabgrass Preventer from the Store – Homeowners 
  5. How do I control crabgrass in spring seeded turf?
  6. Do split applications provide better control than a single application?
  7. How to identify crabgrass?
  8. How will the cool spring affect crabgrass control? Originally posted April 22, 2011
  9. How might a late frost affect crabgrass?
Forsythia blooms are an indicator that crabgrass germination is just around the corner. See the link above "When will crabgrass germinate?"

Newly germinated large crabgrass plant. Photo taken in spring of 2012.
For more information on weed control, search this blog (search box in upper left corner of page) and archived turf tip postings and check out our Turfgrass Weed Control for Professionals Publication

Aaron Patton, Turf Extension Specialist
Read More

How to Select a Crabgrass Preventer from the Store – Homeowners

Crabgrass is a summer annual weed that germinates in lawns each spring (click here for crabgrass identification information). Preemergence herbicides prevent emergence of crabgrass plants from the soil. These products must be applied prior to crabgrass germination which could occur as early as April 1 in southern Indiana and three or more weeks later in northern Indiana in an average year (there don’t seem to be many average years these days). Purdue research has shown that these herbicides can be applied in late winter (February or later) and still be effective all season. It is essential to apply these products early in spring prior to crabgrass germination or they will not be effective and you’ll have crabgrass.

Often, preemergence herbicides are combined with fertilizers. Since fertilization should be minimized in the spring, purchase products with most of the nitrogen in slow release forms such as methylene ureas or sulfur or polymer coated ureas. Avoid products with mostly (>70% of total nitrogen) quick-release nitrogen such as urea or ammonical nitrogen. For more information on fertilizing your lawn, see Fertilizing Established Cool-season Lawns.

Do not use preemergence herbicides on newly seeded lawns or before seeding your lawn – except products that contain siduron (see below images). To be most effective, preemergence herbicides need to be watered-in after application which usually means rainfall in the spring since most irrigation systems aren't yet operational. Refer to the label for specific instructions for each product.

Common Names (Ingredients) of Preemergence Herbicide Ingredients for Home Lawns
  • Benefin/Trifluralin
  • Pendimethalin
  • Dithiopyr – product of choice if you wait to apply until after crabgrass germinates
  • Prodiamine
I listed several ingredients above as our research has shown that all of these ingredients provide similar and effective crabgrass control in Indiana and the greater Midwest.

By maintaining a dense lawn, you can limit the amount of crabgrass. Proper fertility, mowing, and irrigation is essential for crabgrass control; consider herbicidal control only if necessary.
For more information on crabgrass germination and preemergence crabgrass control, see this posting (Common Questions About Crabgrass Germination and Preemergence Herbicides Answered) with multiple articles on this topic linked.

Here are some examples of products that you might encounter at your local store that will work well as a preemergence herbicide to prevent crabgrass emergence. For each I show the picture of the product as well as the “zoomed” in image showing you the ingredient in each.

Close-up of above picture. Same ingredient as the professional product Barricade.

No fertilizer in this product, just the herbicide on an inert carrier.

Close-up of above picture. Same ingredient as the professional product Pendulum.

Similar to Halts Crabgrass Preventer but with the fertilizer (Turf Builder).

Close-up of above picture. Same ingredient as the professional product Pendulum.

Close-up of above picture. Same ingredient as the professional product Pendulum.

Close-up of above picture. Same ingredient as the professional product Dimension. Useful ingredient if you apply after crabgrass germination as it will control crabgrass prior to tillering.

Only preemergence products with siduron are safe to use in the spring  when seeding cool-season turf.

The ingredient in this product is siduron which allows cool-season grasses to germinate but prevents crabgrass from emerging. It is good for seeding but doesn't last as long as other preemergence herbicides so it is not a good season-long preemergence herbicide. This ingredient is sold as Tupersan in the professional market.

Aaron Patton, Turfgrass Extension Specialist
Read More

New Resources Available for Emerald Ash Borer and Pollinator Safety

We are happy to announce two new tools give the latest information about two hot topics: emerald ash borer and pollinator safety.

New Neonicotinoid Pollinator Website available for the Green Industry.
Doug Richmond and I have developed a mobile friendly website to help you answer questions you may have about how the use of neonicotinoid insecticides, like imidacloprid, dinotefuran, acetamiprid can affect pollinators.  We provide specific fact sheets to help you safely protect plants from pest, while minimizing harm to pollinating insects. We also provide links to other resources to provide a science based background about the controversy.

Emerald Ash Borer Self Study Course
Self study courses for the Green Industry and Master Gardeners are now available at the following on our website.
Each course uses 100 slides to guide the student through the history, biology and management of emerald ash borer.  We review the latest tools, for diagnosing EAB and assessing tree health.  We also provide clear suggestions on how to come to an effective management decisions.  These both draw heavily on insecticide recommendations that were revised in June 2014 (  to include how to effectively apply imidacloprid, dinotefuran, azadirachtin and emamectin benzoate.
Students who can pass a 50 question quiz can print a certificate to demonstrate that they have received special training about EAB.

Cliff Sadof, Department of Entomology, Purdue University
Read More

Lee Pilz Memorial Fund

One of our Purdue turf graduates, Lee Pilz died unexpectedly on Saturday, February 21, 2015 in Indianapolis at the age of 39. He graduated from Purdue University in 1998 with a degree in turf science and was the assistant golf course superintendent at Tippecanoe Lake Country Club, Leesburg, IN.

Read Lee’s full obituary here.

The Hoosier Golf Course Superintendents Association has established a memorial fund for Lee’s family to help support Lee’s wife and three daughters. Please consider donating at the Hoosier GCSA website.
Read More

Weed of the month for February 2015 is Dandelion


Biology: Dandelion (Taraxacum officinale), is a broadleaf perennial weed that can be found in lawns, nursery crops, and landscapes throughout the United States. It has the ability to survive many different soil types, environmental conditions, and management practices; thus, it is a commonly found weed in lawns throughout the northern half of the U.S.

Identification: Dandelion is one of the most identifiable broadleaf weeds. It is a perennial broadleaf that is a member of the composite or daisy family. It prefers full sun and grows best in moist soils; however, it can survive in multiple environmental conditions (shade and heat) and management practices (fertility, drought, low mowing practices). Dandelions generally appear in early spring as they regrow from a few overwintering leaves and their taproot. Leaves have distinct wavy margins that form into the irregular ‘toothed’ appearance that makes the plant easily identifiable. The ends of the ‘teeth’ tend to point down towards the base of the rosette.

Dandelion produces a strong taproot and the plant has the capability to regenerate from surviving taproot segments (so hoeing a dandelion from your garden may not actually kill the plant). The survivability of this taproot helps to make dandelion a very prevalent and ‘difficult to completely control’ weed in lawns in Indiana, even following herbicide applications.

Dandelions typically flower from late April to mid-May in Indiana. Yellow flowers consisting of sunflower-like petals, are produced at the ends of long, leafless, erect stalks. Dandelions typically flower in their second year of growth after germination from seed. Yellow-brown fruit (flowers) are formed into a conspicuous, globe-like, white seedhead with light, feathery ends capable of easy dispersal by the wind. Each seedhead is capable of producing 140 to 190 individual viable seed, which helps to contribute to the vast populations of dandelion located in lawns throughout the Midwestern United States. Dandelion seeds germinate in emerge from late spring (after flowering and seed dispersal) to early autumn.

Dandelion may often be mistaken for chicory since both form toothed leaves that form from a basal rosette. However, the basal leaves of chicory tend to be rough to the touch with distinct, coarse hairs. Additionally, the toothed lobes of chicory are often alternately arranged on the leaf and point both backward and forward, while the toothed margins of dandelion are located opposite of each other on the leaf and predominantly point backward. The most distinct difference between the two plants is that dandelion produces yellow flowers while the flowers of chicory are purplish-blue in color. 

I am not sure who created this .gif movie of dandelion flowering, but it is amazing.

Cultural control: None known specifically for dandelion. Digging up as much of the taproot as possible will improve control. Dandelion knives and other similar tools are available for removing individual plants with very little disturbance to the soil. These tools, however, are only effective when all the taproot is removed. Adjusting fertilization practices to minimize the about of potassium (K) or potash (K2O) may help to reduce dandelion populations, but this process is very slow to generate results (many years). Management practices such as increased mowing heights, fertility, and irrigation may help to produce a dense vigorous turf capable of outcompeting germinating dandelion plants.

Biological control: The fungus Sclerotinia minor can selectively remove dandelions from cool-season lawns. In Canada it is formulated and sold as Sarritor, a new biological weed control product. This product has yet to be released in the US as of 2015.

Chemical control: Many herbicides effectively control dandelions, especially those that contain 2,4-D. Fall is the best time to control perennial broadleaves like dandelion, and both amine or ester formulations of 2,4-D provide optimum dandelion control in the fall. If dandelions are problematic in the spring, dandelion control can be optimized in the cooler months (April) by using ester formulations of broadleaf herbicides, or by using florasulam (Defendor). However, even ester formulations can be ineffective if applied too early. As spring progresses and temperatures warm, turf managers should switch from ester formulations of broadleaf herbicides to amine formulations because (1) their efficacy improves during warmer temperatures in May and early summer and (2) they are safer than ester formulations to use around landscape plantings, gardens, and other sensitive plants. For more information about using amines or esters, see “Should I use an amine or ester formulation for postemergence broadleaf weed control?” in" Turfgrass Weed Control for Professionals."

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

For archives of past weed of the month postings, visit our Weed of the Month Archive.

To become a true dandelion aficionado, check out this publication from the Canadian Weed Science Society: click here

Aaron Patton, Turfgrass Extension Specialist, Purdue University
Leslie Beck, Weed Extension Specialist, New Mexico State University
Read More