Ascochyta Leaf Blight: Facts and Myths

Tony Koski, Extension Turf Specialist
Dept. of Horticulture and Landscape Architecture

The visible wheel tracks does NOT mean that mowing 

"tracked" the ALB fungus on to the lawn. Rather, the 
lawn was drought-/heat-stressed when it was mowed. 
The wilted grass leaves were killed by the weight of 
the mower - but the grass plant is still alive.

It's back, in full force, on Colorado's lawns. Cool, wet springs, like this year's, create perfect conditions for Ascochyta leaf blight (ALB) outbreaks. When the transition from spring to hot, dry summer conditions occurs as suddenly as how it happened this year, ALB becomes epidemic in lawns.

We've blogged about ALB a number of times, so there's no reason to repeat what you can read there (2013, 2015, 2016, 2017). Without re-hashing what was written in years past,  the most important takeaway: it's a problem of drought, heat stress, and lack of water (or a sign of an irrigation system problem); mowing the stressed turf often increases the injury. The good news is that the grass is NOT dead, but can be revived with sensible watering and by paying closer attention to future irrigation needs.

Some ALB facts:

• While it is a disease, ALB is really a problem of water - not enough, or not frequently enough. 
• ALB can affect bluegrass, fescue, and ryegrass lawns.
• Fungicide applications will NOT make it recover more quickly - so don't apply them (or don't pay for your lawn care company to apply them!)
• While an ALB outbreak looks terrible and the grass appears dead, this disease does NOT kill grass.
• An infected lawn will recover, though it may take 1-3 weeks for full recovery. Recovery rate depends on severity, species of grass, and how you water (not swampy, but consistent moisture).
• Light fertilization - if your lawns has not yet been fertilized this year - can help speed recovery.
• The ALB fungus does infect grass leaves through the mowed off tip of the leaf blade - but that doesn't mean you should stop mowing the lawn when disease is active (mowing doesn't spread the fungus, nor does it significantly increase the amount or severity of the disease). 

Some popular myths about ALB:

• Maybe you've read on the never-wrong internet that the ALB fungus is spread by mowers? Wrong! The wheel tracking often seen on ALB-affected lawns occurs because the lawn was mowed when it was drought- and/or heat-stressed. The weight of the mower crushes the wilted leaves under the wheels, leaving brown tracks a day or so later. Often there is no ALB disease IN the wheel tracks - but plenty of blighted turf between the wheel marks. 
• You will also find claims that lawn mowing equipment should be disinfected between lawns - or after you mow you own lawn. Wrong again! The fungal spores that can result in ALB are everywhere already. Disinfecting your mower with bleach solutions or Lysol will not prevent future ALB on your lawn, nor will it prevent its occurrence on lawns of other clients (if you own a lawn care or mowing business).
• You will also read on that you should throw grass clippings from lawns suffering an ALB outbreak into the trash, because leaving them on the lawn will make the problem worse - or will cause it to happen in the future. Again, there is no evidence to suggest this to be true. As before, the spores are EVERYWHERE already. Grass clippings can be safely composted or used as mulch in gardens (because the fungus causing the lawn disease doesn't affect vegetable or flower garden plants).

While people will always claim that "it can't be water", it ALWAYS is. When you can see where the sprinkler heads are in a lawn affected by ALB, that should be a sure indicator that it is a watering issue. Read the previous blogs listed above for suggestions on getting a lawn back to health after an ALB outbreak.

Be Gone, Grass (in landscape beds)!

 Posted by: Alison O'Connor, Larimer County Extension

Do you battle grass creeping into your landscape beds? Me too. And it isn't fun dealing with it. I've tried all the recommendations--pulling, mowing, digging, and herbicides. Now, before you label me as a "spray head", I'm not. I pull a lot of weeds in my landscape, mostly because I find it therapeutic. I love listening to music, filling up a bucket of weeds, and appreciating my landscape on a micro-level. However, I also have my limits, and trying to dig out bluegrass around my delicate plants isn't fun.

Kentucky bluegrass creeping in my Heuchera (coral bells).

Fortunately, the herbicides available for this problem are extremely effective and readily available. If you choose not to use herbicides, then keep on keepin' on with pulling, digging, and using mulch. These efforts can be successful, but persistence is key. Do it regularly.

If you want to consider herbicides, then look for products that contain either fluazifop or sethoxydim. There's a third, clethodim, but it tends to be more expensive. These herbicides are sold in products like Ortho Grass B Gon, Fertilome Over the Top II, Bonide Grass Beater, Monterey Grass Getter, etc.  

One of many options you can use to selectively remove grass from landscape beds.
This is not an endorsement of any particular product. 

[Side note: I absolutely LOVE saying "fluazifop" and find it to be the most fun chemical name to use in everyday conversation. Flew-as-uh-fop. Fabulous.]

These are selective herbicides, meaning they will remove grass selectively from other plants. Namely, they will kill grasses, but leave your broadleaf plants unharmed. But they can injure/kill other grasses (ornamental grasses), iris, and other monocots. So read the label and use carefully.

But they do work! And usually in one application.

Use of fluazifop in my front landscape bed on bluegrass;
nearby plants included sedum and spring bulbs.

Don't worry, sedum, help is on the way!

Hang tight, little sedum, you'll be free from that bluegrass soon.

Why CSU’s New Stadium Should be Real Grass – and why it Probably Isn’t

Tony Koski, Extension Turf Specialist

Hughes Stadium turf  (yes, real grass!) in 2002, the night prior to
an epic nationally televised Rams victory over Louisville (36-33). It
WAS the best playing surface in the Mountain West Conference.

This past Monday it was announced that CSU’s freshman sensation quarterback, Collin Hill, suffered a season-ending ACL injury during Saturday’s victory over Utah State (you can read about it here). Why am I writing about this in a blog focused on horticulture? Stick with me, even if you aren’t into sports or aren’t a CSU football fan, and you will hopefully see the connection.

As noted in the article, this was a non-contact injury – meaning that Hill wasn’t injured by being tackled or hit by another player. Quoting CSU coach Mike Bobo: “It was non-contact. He was just planting off his left foot, and it buckled. Tough thing for Collin, tough for our football team.” Just bad luck, right? Football injuries happen – usually the result of a collision with another player, being tackled, being fallen upon, etc. And, yes, injuries happen on both types of field surface – synthetic and natural grass. But does it really matter if football is played on grass or synthetic turf?

A close-up of the old Hughes Stadium natural grass playing surface.
Better than synthetic!

Companies that promote the use of their synthetic turf over natural grass for athletic fields vigorously state that their synthetic surfaces are safer for athletes, less expensive and easier to maintain, that they are environmentally friendly – and that they are “just like real grass” (OK, so why even bother with the comparison, if you are better?). These claims are made during the “sell” to athletic directors, coaches, booster groups, school boards, city councils, etc. The claims (especially about money and cost-savings) make it seem like the decision to use synthetic over real grass is a no-brainer and that it would be irresponsible to spend money on grass fields. These “selling points” work – even on otherwise intelligent people – because there is RARELY anyone present when decisions are made to provide evidence to the contrary: that natural grass MIGHT be a better choice than synthetic for a HOST of legitimate, provable reasons.

It was such a big game that there were 2 Cams
there for some reason? They could (and did!) graze
on the stadium turf then. And it was safer for the
players too!

I will honestly state that synthetic turf, in some situations, is often the VERY BEST playing surface for a school to install. But there are so many times when it can be argued that real grass is the most sensible, common-sense choice. The problem is that decision-makers often don’t ask the right questions (about safety and cost), discount and ignore arguments for using real grass, believe without question what the synthetic companies claim, and often bow to the sentiment that “everyone else is doing it, so we have to because it must be the right thing to do”.  Often, the promise of funding to install synthetic (but ONLY synthetic because that’s what a donor or booster group wants for their team or their coach) overrides any other reasoning to consider grass. Worse still, the decision is often made by a coach – who is both highly unqualified to make such an important decision and is also highly unlikely to still be coaching that team when that synthetic turf needs to be replaced.

I could write an entire blog on cost comparisons of installing, maintaining, and replacing the two types of surfaces – but perhaps some other time. However, if you want to read some very compelling evidence that synthetic often does NOT make financial sense, here is an excellent article in Forbes magazine on the topic entitled “How Taxpayers get Fooled on the Cost of an Artificial Turf Field”. It’s quite lengthy, but compelling and difficult to argue with – unless you are a synthetic turf company that isn’t totally forthcoming on costs of maintenance and replacement. The national Sports Turf Managers Association (STMA) also provides a great comparison of costs to maintain these different playing surfaces. Fodder for a future blog!

More important than cost, however, is safety. Which is safer for football players from an injury perspective: grass or synthetic? Synthetic companies will tie themselves in knots to make synthetic appear safer for athletes than real grass. But what does research say about injuries on these two surfaces?

Divots in a natural grass field act as "circuit breakers" when a player's
foot locks in the turf - giving way so that the ligaments and tendons
in knees and ankles are less likely to.

In a study entitled “The effect of playing surface on the incidence of ACL injuries in National Collegiate Athletic Association American Football”, the authors analyzed the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS) men's football ACL injury database from 2004-2005 through 2008-2009 to determine what effects that playing surface might have on ACL injury in NCAA football athletes. They found that the rate of ACL injury on artificial surfaces is 1.39 times higher than the injury rate on grass. Specifically, they found that non-contact injuries occurred more frequently on artificial turf surfaces (44.29%) than on natural grass (36.12%), and concluded that “NCAA football players experience a greater number of ACL injuries when playing on artificial surfaces.” This begs the very simple question: why install a playing surface (when you have a choice) that is PROVEN to increase the potential for injury to student athletes?

In a similar study that examined injury rate in NFL players (An analysis of specific lower extremity injury rates on grass and FieldTurf playing surfaces in National Football League Games: 2000-2009 seasons), the authors found that “the observed injury rates of ACL sprains and eversion ankle sprains on FieldTurf surfaces were 67% (P < .001) and 31% (P < .001) higher than on grass surfaces and were statistically significant”. No comment needed on these numbers, as they speak for themselves! (FieldTurf is a specific brand of synthetic turf, and is what is currently installed in Hughes Stadium).

While not a Baltimore Ravens fan (remember that awful playoff game in January 2013?), they are to be applauded for replacing their synthetic field with real grass this year. The Ravens players lobbied ownership to make the change to grass. “To a man, players said they would rather play on natural grass than artificial turf,” says Don Follett, M&T Bank Stadium’s senior director of fields and rounds. “That’s consistent with NFL surveys showing that 90 to 95 percent of the league’s players prefer real grass. They say it feels better under their feet and provides a softer landing when they get knocked down. If your players feel better, they’re more likely to play better for you, and that carries a lot of weight.”

Rendering of new CSU practice fields (Source: CSU Source; Colorado State
University)

Finally, another article in the Coloradoan this week noted that construction on a new SYNTHETIC practice field adjacent to the new stadium will begin this Saturday. It is part of a larger project that will “… serve as a gateway to the stadium, with plantings to celebrate and demonstrate the university’s agricultural heritage”. Simple question: how does a carpet covered with smelly, ground-up rubber celebrate “agricultural heritage”? Just asking....

Contrary to many of my colleagues here at CSU and possibly many readers of this blog, I was (and still am) fully supportive of the new stadium. But that doesn’t mean I can’t ask the question: why install a playing surface that is proven to increase the potential for injury to student athletes when we have the opportunity and resources available to install real grass? After all, if the CU Buffaloes can maintain a real grass stadium (used for graduation, as a stage for the Boulder Bolder, and to host concerts and numerous other events), certainly Colorado’s Land-Grant university could do the same? Go Rams... but don’t let Cam do any grazing on your fields.

University of Colorado's beautiful grass Folsom Field
(Source:Kai Casey/CU Independent)

Grassology

Posted by: Tony Koski, Extension Turf Specialist

I guess I don't watch enough late night TV? Or maybe I have to pay more attention to the commercials? I had never heard of Grassology...until I received this email from Penni A. a few days ago.

Greetings Dr. Koski,

I was wondering if CSU has written anything on the product called Grassology? I’m embarrassed to say “As Seen on TV” but it does sound so good I thought I would ask the experts at my alma mater CSU.  I ruined my grass by purchasing years ago what they called drought grass.  Now I battle weeds and aggressive clover type plants regularly.  I don’t want to waste your time but if you could direct me to information on a better grass for Denver I would appreciate it.

Sincerely,
Penni A

Coincidentally,  that very afternoon I was in a Bed, Bath and Beyond (I still have yet to find the "Beyond" section of BB&B), where a display of - you guessed it - Grassology was located just inside the front door. I didn't even have to do a Google search. There it was...with Bob Vila's smiling face staring at me. That just about sold me. I mean, if Bob endorses it, it must be good? But my Extension senses returned to me...and healthy skepticism took over. Grassology: the Science of Grass. Breakthrough. Patent pending. As seen on TV. I can hear Bob's friendly, convincing voice now.... "no more high water bills...or weekly mowing... or ongoing fertilizing...or constant weeding." Only $19.99. For 3 pounds. So worth it! I can see the attraction Penni. But being a super smart CSU alum, you wanted to know more. And now so did I. If you go to the Grassology website you find little real product information - like what kind of grass it is!? Ahh, but you can listen as Bob V. makes those irresistible, sound-too-good-to-be-true claims.

While the website provides little useful information about Grassology, the seed label on the bag (required by law) is much more revealing. Grassology is a mix of fine fescues, tall fescue, Kentucky bluegrass, perennial ryegrass - with a few weed seeds thrown in. In many ways, this is a horrible product. First, this mixture of grass species will grow into a patchwork of different textures and colors. Second, this is all "Variety not stated" (VNS) seed. There are no variety names listed for any of the species - a dead give-away that this is a low-quality product that no reputable seed company would sell to anyone (except to people who either don't read the seed label... or who don't understand what "VNS" means - which is most everyone who is not a professional turf manager). Third, the amount of Weed Seed (0.05%) is a large amount of weed seed for a turf product; with a little effort, the homeowner can find good quality turf seed that is 0.00% weed seed. Finally, the cost of this product borders on the outrageous. Three pounds of seed for $19.99 - which works out to $6.66 per pound (a devilishly scary number!). And even more: this is coated seed (to theoretically aid in germination), so there is really only a little more than 1 1/2 pounds of seed in the bag! Readers of this blog in Colorado can purchase premium quality seed (named varieties - the same stuff that sod producers and golf course superintendents buy) from a number of Colorado seed companies - and at a much lower cost per pound than this stuff. 

There is nothing revolutionary or new in Grassology. The grasses in this mix have been around for years and are used in lawns today. The smart CSU alumnus she is, Penni was wise to question this product's claims. And so should any of you thinking about purchasing Grassology. I know that Bob Vila sounds so smooth and convincing, but if it sounds to good to be true... 

Tempted by the Cutting Edge?

Posted by Tony Koski, CSU Extension

In the past few months I’ve received a bunch of calls and emails about a “revolutionary” (the company’s words) product – CuttingEdge grass seed. I had never heard of this stuff. I’ve been asked…”What is in it?”… “Should I buy it?”….”Is it better than what I have now?”…. “Isn’t it just grass seed?”…. and “It sounds too good to be true…Can it really be that good?”.  Beyond what they found on the company website, people could find no information on it anywhere on the Internet. So I did what we do in Extension: I tried to find out what I could – especially any research-based information.

 

Surprisingly, I could find little on this product as well – except on the company website (www.cuttingedgegrass.com).  One look and I understood why all of the questions. This stuff is incredible! It (Cutting Edge Grass Seed) not only has “unique characteristics that revolutionize the way grass seed and turf management is viewed today.”, but it is “one of the most environmentally responsible grass seed mixes sold anywhere in the world.”.  Those are pretty big claims? But…wait… there is more! A lawn planted to this grass could allow you to STOP (their emphasis) “constant” (their word) watering, fertilizing and mowing. It will grow roots up to 48 inches deep. It is salt resistant, endophyte-enhanced, self-repairing, grows in sun or shade, and is resistant to gray leaf spot. It comes with an OMRI-approved “hydration and mycorrhiza” coating. You can even earn points towards LEED Certification by planting it (intriguing, though that link was dead). Wow! Amazing! I’ve got to try it!

Just as I was about to click that big red “Order Now” button that promised an extra FREE 1 pound bag (Well…free, except for more shipping and handling…) if I bought 1 pound, a thought crept into my head: what IS this stuff? I scoured the flashy (and really slow) website. All I could find was that it is a “patent-pending mix of Kentucky bluegrass and other top-performing seed.”.  Hmmm…now I’m suspicious. And annoyed. Really annoyed. I hate it when a company won’t say what is in their product – especially when it’s required by law. 

Instead of the “Order Now” button, I clicked “Contact” and dialed the information number. I got a live, knowledgeable, friendly person – Kristin – who answered all of my questions. (Disclaimer: I told her up front that I was gathering information for this blog) I asked what, besides Kentucky bluegrass, was in the mix (I was told perennial ryegrass, hard fescue, Chewings fescue, and tall fescue). When I asked about cultivar/variety names, Kristin said the company doesn’t reveal those. I asked if the mix contained VNS seed (stands for “variety not stated”), and was told “yes, it is VNS seed”. Ahhh...the reason they can’t tell you the cultivars – because they are not sure of what those cultivars are! To be fair, VNS is not always “bad seed”; it CAN be very good seed, in fact. But buying VNS seed is like ordering “running shoes” from Zappos and not being able to specify size, brand, style, or color. You will get running shoes, but will they fit your feet, fit your needs – will they be what you want? Kristin also kindly sent me a sample label for one of their seed lots (the seed lots will differ slightly, she told me, depending on where in the country you order your CuttingEdge seed).

The company recommends a seeding rate of 4 pounds per 1000 square feet – which is about 1.6 pounds of seed (because of the coating on the seeds…which is about 60% of the total weight). This would be a low rate for bluegrass alone, much less for the larger-seeded rye and fescues (which comprise about 80% of the seed in this mix). To end up with a turf of acceptable density using this product, it should be seeded at a rate of 12-15 pounds of the coated seed per 1000 square feet – not 4 pounds.

To seed 1000 square feet, using the company’s recommended seeding rate, it would cost about $40 (if you buy the 10 lb. professional kit; about $72 if you buy the one pound bags). To seed at a rate that would give any chance of producing good quality turf, it would cost about 3-4 times as much ($120-280….to seed 1000 square feet of turf!).

If you were to instead buy a comparable seed mix (bluegrass/fine fescues, or bluegrass/ryegrass) from a reputable local seed company like Pawnee Buttes Seed (http://www.pawneebuttesseed.com/seed-list/mixes/) and seed at a rate of 6 pounds of seed per 1000, it would cost $12-18 dollars for seed.

Though it’s possible that the VNS seed sold by CuttingEdge is of good quality, the product cost (quite high) and recommended seeding rate (quite low) make this product an unwise buy. And the idea of mixing grass species like bluegrass, ryegrass and fescues is far from “cutting edge” or revolutionary – much less a patentable one. It’s far wiser – both agronomically and economically – to purchase seed of excellent quality and known cultivars from a local, reputable seed company. You will know what you are purchasing, get the best quality seed, and won’t have buyer’s remorse later. It may not seem sexy or cutting edge, but it’s smart. CuttingEdge grass seed: another case of “If it sounds too good to be true….”