What To Do With All Those Falling Leaves?

It is that time of year when leaves are falling faster than you can rake them in many places. It is important to rake leaves when there are many leaves on the ground (so many that you can't see the turf underneath) so that heavy layers of leaves will not shade out, smother, and kill turf. However, when only a moderate number of leaves are on the ground, you can use your mower to mulch them back into the turf. Research results at Purdue and other universities demonstrates that:

• Tree leaves (both oak and maple) can be mulched without any detrimental effects on the soil or turf and usually results in improvements in soil structure.
  
• Mulching leaves into the turf will not increase thatch or disease.
  
• Leaves have no effect on soil pH and no measurable effect on nutrient availability.
  
• Mulching leaves will not result in increased weed pressure and some recent research in Michigan even suggests that mulching leaves back into your lawn can reduce dandelion populations.
  

Helpful tips:

• The easiest way to dispose of leaves is to simply mow them into the turf.
  
• Regular mowing during the fall will chop the leaves into small pieces and allow them to filter into the turf.
  
• Dry leaves mulch more easily and readily than wet leaves.
  
• Mulching leaves with a mower is much easier and less time consuming than raking, blowing, and/or vacuuming the leaves like we have done in the past.
  
• Mulching leaves disposes of the leaves without filling up our landfills and saves our municipalities thousands of dollars in disposal costs.
  
• Do not burn leaves because of our current burn bans and due to environmental pollution.
  
  
   
  
  
  
   

Aaron Patton, Turfgrass Extension Specialist

Winter Annual Weeds

Four types of broadleaf weeds exist: 1) perennial (those living more than two years), biennial (those living two years), 3) summer annuals (those germinating in the spring and dying in the fall), and 4) winter annuals (those germinating in the fall and surviving the winter and dying the following spring). Since many of these winter annual weeds are now germinated, I thought it might be a useful exercise to review their identification. Below is one picture of various winter annual broadleaf weeds. Be on the lookout for these this fall and next spring.

Annual bluegrass

Catchweed bedstraw

Common chickweed

Corn Speedwell

Henbit

Prickly lettuce

Purple deadnettle

Sheperd’s purse

Aaron Patton, Turfgrass Extension Specialist

Imprelis Return and Refund Program

On October 17, DuPont began a process to recall and refund Imprelis from Turf professionals. DuPont has contacted distributors, who will be coordinating with turf professionals to ensure that all remaining full and partially full bottles of Imprelis® are returned. Turf professionals have 10 business days to return all Imprelis® product (4.5 fl. oz., 1.0 gallon, and 2.5 gallon bottles) to them after the initial contact from the distributor. After returning the remaining Imprelis® to the distributor, turf professionals will be given either a refund or credits, depending on the distributor’s policy. In this EPA approved disposition plan, the EPA suggests that you maintain records associated with Imprelis®, including but not limited to: 1) quantities used and returned, including product lot numbers 2) application records, and 3) purchase records.

Below are links to documents useful to turf professionals who applied Imprelis® last fall or this spring. More information is available at http://www.imprelis-facts.com/ and at (866) 796-4783.



Information From DuPont:

Imprelis Status Mailer to Users & Dealers (September 20, 2011)

DuPont Imprelis return & refund letter to applicators (October 17, 2011)

DuPont Imprelis return & refund letter to distributors (October 17, 2011)

DuPont Imprelis instructions for return & refund (October 17, 2011)

Grass Clippings and Herbicides

I have received a few questions recently regarding the use of grass clippings on lawns treated with herbicides. Here is one of those questions: “Our Master Gardener Association will be working on a project in which they hope to use a great amount of lawn clippings to put down as compost in a large area. This will require lawn clippings donated from several different sites. Will they run into a problem with clippings from lawns that have been treated with Imprelis® this year? Would there be chemical residue which remains in the clippings and/or compost which should be avoided?”

The answer to that specific question is that we do not recommend that clippings from lawns treated with Imprelis® (aminocyclopyrachlor) be used in the composting. Even if Imprelis® was applied 6 months ago (applied in April, today’s date October 12) there still could be some Imprelis® residue present in the clippings or the soil. Although any herbicide residue may be minimal from a spring application, we 1) don’t fully understand how long Imprelis® lasts in the soil or the grass clippings and 2) Imprelis® is active at very low rates and thus even if just a little is left it could be enough to cause injury on a susceptible ornamental plant such as tomatoes in the garden or flowers in the landscape.

The Imprelis label states “Do not use grass clippings from treated areas for mulching or compost, or allow for collection to composting facilities. Grass clippings must either be left on the treated area, or, if allowed by local yard waste regulations, disposed of in the trash. Applicators must give verbal or written notice to property owner/property manager/residents to not use grass clippings from treated turf for mulch or compost.”

The Imprelis® label does not state how long not to remove clippings. Eternity, 1 year, 2 months? It simply does not say. Therefore, I recommend not to use clippings from Imprelis® treated lawns in compost.

What about other herbicides? Other herbicides applied to residential turf may have label language as well that restricts clippings from being collected. The Dimension® 2EW (dithiopyr) label also states “Do not use clippings from treated turf for mulching around vegetables or fruit trees.” Like the Imprelis® label, the Dimension® 2EW label also does not specify how long to wait after treating before clippings can be safely harvested. Another herbicide, Drive® XLR8 (quinclorac), states that “Clippings from the first three mowings after application should be left on the treated area”. This label makes it a little clearer when it is safe to harvest clippings. Most labels contain no reference whatsoever to “clippings”.

Therefore, language varies from label to label regarding the use of clippings for mulch or compost following a herbicide application. In most cases I would recommend not using clippings from a lawn treated with herbicide within one-month (approximately 3 mowings) unless the label states otherwise such as with Imprelis®.

Aaron Patton, Turfgrass Extension Specialist

MRTF Turf and Ornamental Seminar - November 14-15

Turf and Ornamental Seminar

November 14-15, 2012

Daniel Turf Center

West Lafayette, Indiana

Registration Form (PDF Format)

Register on-line at http://mrtf.org/php/Registration.php?pid=5487

Registration Deadline: November 2, 2012

CCH's: Cat. 2 - 5 CCH's; Cat. 3a - 8 CCH's; Cat. 3b - 9 CCH's; Cat. 6 - 3 CCH's; RT - 4 CCH's

Wednesday, November 14

8:00-8:30              Registration

8:30-8:45              Opening comments, Aaron Patton

8:8:45-9:45          All About Turf Seed: Identification, Germination, Planting, Aaron Patton

9:45-10:45           Safe Tree Felling: What You Need To Know, Lindsey Purcell

10:45-11:45         Getting Your Hands Dirty: Learning More About Soils, Quincy Law

11:45-12:45         Lunch (on your own)

12:45-1:40           Selection and Inspection of Spray Hoses and DOT Rules, Fred Whitford

1:40-2:00              DOT Regulation Changes: What You Need to Know, Fred Whitford

2:00-3:00              State Chemist News and Updates, Joe Becovitz

3:00-4:00              Weather Effects on Insects: How Do Insects Cope?, Tim Gibb

Thursday, November 15

8:00-8:30              Turf Jeopardy, Aaron Patton

8:30-9:30              New Tools For Managing Landscape and Ornamental Insect Pests, Cliff Sadof

9:30-10:30           Maintaining Grounds: Keeping Native Species In and Invasives Out, Matt Kraushar

10:30-11:30         Perennial Disappointments: Diseases of Perennial Plants, Janna Beckerman

11:30-12:15         Lunch (provided)

12:15-1:15           Promoting Turf Recovery…Fertilizer Strategies, Seeding and More!, Cale Bigelow

1:15-2:15              Identification and Control of Turf Diseases, Rick Latin

2:15-3:15              Herbicide Update: New Resources and Ingredients, Aaron Patton

If you have any questions or have any special dietary needs please contact Jennifer Biehl at 765-494-8039 or biehlj@purdue.edu

When a GPS Unit Malfunctions

This photo was submitted from a golf course where it was found tunneling into a green.  It is obvious that it is creating some damage but the astute manager was able to find and photograph the beetle in association with the damage.  This combination always makes identification and control recommendations much easier.

The insect was identified as a ‘Fancy Dung Beetle’ in the family Geotrupidae: Bolbocerosoma sp.   It is closely related to the Scarabaidae (Japanese beetles, masked chafers, June beetles etc) that we are very familiar with.  Like the Scarabs, these insects often bore down into the soil to lay their eggs.  Usually Geotrupid beetles select areas very rich in decaying organic matter such as in manure and barn yards.  However, just like people, every so often one will become completely lost.  This one apparently has ended up on a golf green by accident.  

You can see that the beetle has created a bit of a burrow and this may be a concern if many of his kind were to do the same thing on a green.  However, I think this may be just a random occurrence and the damage, a very isolated incident. Why it is where it is nobody knows for sure.  I suspect that it’s GPS system is simply out of whack.


Timothy Gibb, Department of Entomology, Purdue University

Weed of the month for September 2014 is Broadleaf Plantain

Broadleaf Plantain  

Biology: Broadleaf plantain (Plantago major) is a perennial, broadleaf weed that can be found in nutrient-poor soils; however, they prefer nutrient rich-soils that are moist and often high in calcium. Broadleaf plantain is a common weed in turfgrass, nurseries, and landscapes as it can tolerate very low mowing heights. It germinates from seed in late spring through mid-to-late summer and occasionally in the fall depending on temperature and moisture. It has a low growing rosette habit and tolerates close mowing. It's ability to surve a range of environments make broadleaf plantain a common turfgrass weed in North America.

Identification: Broadleaf plantain is anchored primarily by fibrous roots. Some describe the root system as having a central, short taproot with branched-out fibrous roots but my experience is that large, fibrous roots are common and that taproots (especially large taproots like a dandelion) are very uncommon. Broadleaf plantain grows with a rosette habit with leaves that can grow flat along the turfgrass canopy or more erect and upright depending on mowing practices. The plant produces leaves that form on long, broad leaf-stems (petioles) that may grow up to six inches long and four inches wide when left unmown or untreated. Young leaves are oval to egg-shaped, generally have 3-5 prominent veins, and are light green in color. As the plant matures, the leaves start to appear darker green, can be smooth or slightly hairy, and abruptly narrowing to the petiole (leaf stalk). Very prominent leaf veins run parallel to the margin and appear to originate from the attachment point at the petiole. Leaf margins are smooth (entire) and appear more crinkled and wavy as the plant matures. Though the leaves can appear waxy and dark- to bluish-green, the petioles often have a reddish color towards their base, or the origin point of the rosette. Broadleaf plantain can produce flowers from June through September on long, leafless flower-stalks that arise from the center of the rosette. Small, whitish petals emerge from the flower-stalk where seeds are produced in an oval-shaped capsule which can contain up to 30 viable seeds. It may often be confused with blackseed plantain (Plantago rugelii) which is similar in appearance. Additionally, it is thought that many plants characterized as broadleaf plantain may in fact be natural crosses between Plantago major and Plantago rugelii.  

Broadleaf plantain appearance in early spring. it will regrow all its leaves each spring. The purple coloring here is in response to cool, spring temperatures.

Cultural control: None known specifically for broadleaf plantain. Since its primary method of dispersal is through seed, control or removal of the plant prior to seed production could reduce the spread of this weed. However, mowing practices alone to remove the seed stalks will not provide adequate management since the plant can produce viable seed at low mowing heights (produces viable seed at about 2 inches and taller heights of cut). Proper turf management such as higher mowing heights, irrigation, and fertilization will help to produce a dense, aggressive turf which is the greatest defense against invading/germinating weeds. Broadleaf plantain thrives in compacted soils, moist or dry soils, and shady conditions. Some research suggests as well that this plant prefers high calcium soils, but high calcium soils are a common phenomenon in North American because the soil parent material is limestone. Plants can be removed by hand-weeding if there are only a few on the property.

Biological control: None known specifically for broadleaf plantain. Many new organic products contain the active ingredient iron HEDTA (FeHEDTA). Multiple applications of this product are required for control. FeHEDTA containing products injure turf less (can actually make turf darker green), but their efficacy for weed control is yet to be well documented.

Chemical control: Broadleaf plantain can be chemically controlled with several products such as repeat applications of two- or three-way mixtures of 2,4-D, dicamba, MCPP, or MCPA which are available in multiple formulations at local retailers. 2,4-D is the active ingredient that does most of the work in these mixtures. Herbicides that contain triclopyr (Turflon Ester) or triclopyr in combination with other herbicides, such as 2,4-D, can also provide good broadleaf plantain control in cool-season grasses.

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

Leslie Beck, Postdoctoral Research Associate