Tuomey Turfgrass Consulting is a proud member of these fine organizations:
NALP (National Association of Landscape Professionals) is the national trade association representing more than 100,000 landscape industry professionals, who create and maintain healthy, green living spaces for communities across America. PLANET members are committed to the highest standards in industry education, best practices, and business professionalism.
The Virginia Turfgrass Council - The VTC is a 53 year old organization whose mission is to unify efforts to promote turfgrass improvement and advancement of the turfgrass industry in the Commonwealth of Virginia.
Virginia Nursery and Landscape Association - VNLA is the commonwealth's trade association for garden centers, nursery growers, landscape designers, installation and maintenance contractors, greenhouses and horticultural suppliers. Their mission is to unify, strengthen and promote the Green Industry and maintain, promote and certify industry practices and principles that keep Virginia green and growing.
Maryland Nursery Landscape and Greenhouse Association - MNLGA's purpose is to promote the use of ornamental plants, products and services. MNLGA supports all constituent groups of the horticulture industry including landscape, garden centers, interiorscape, grounds maintenance, nursery, greenhouse and arboriculture. The association communicates the role of the horticulture industry in improving people's quality of life. .
We have the following certifications:
Certificate in Turfgrass Management - The University of Georgia
Certificate in Horticulture - PLANET
Certified Fertilizer Applicator - Commonwealth of Virginia, Department of Agriculture
Certified Fertilizer Applicator - New Jersey Department of Environmental Protection
Certified Fertilizer Applicator - Maryland Department of Agriculture
Certified Nutrient Management Planner - Commonwealth of Virginia, Department of Conservation and Recreation, Division of Soil and Water Conservation
In this section, I will be discussing turfgrass diseases. I understand your average turfgrass warrior may not have the training or experience to successfully diagnose and treat turfgrass diseases. But, my intent here is to perhaps make you warriors aware of the various diseases. And, perhaps, you will be able to understand more if you think your turf area has a disease. At that point, you can call in a guy like me for some fire support.
As I say all the time, the best way to fight disease, drought, weeds and other stresses to your stand of turfgrass is to have a thick, healthy stand. Once you get your stand going, if one of these diseases does strike, then you may need to do some analysis, some soul searching and perhaps take some other courses of action.
Diseases for most plants can be caused by forces of the physical and biological environment surrounding the plant. These diseases can be divided into two categories: noninfectious and infectious.
Noninfectious diseases are usually caused by nonliving agents like a surplus or deficit of fertilizer, a chemical spill or environmental stresses like high or low temperatures, drought or salinity. Mowing improperly or heavy traffic can also be considered a noninfectious disease injury.
The pathogens associated with infectious diseases are: fungi, viruses, bacteria and nematodes. Most of the turfgrass infectious diseases are caused by fungi. Before modern methods for analysis, scientists thought fungi were part of the plant kingdom. But, fungi do not have chlorophyll and are unable to produce their own food through photosynthesis. Some fungi feed on the dead leaves, stems, and roots of our beloved turf.
A fungus (the singular form, the plural form is fungi or funguses) begins when a spore or sclerotium (plural is sclerotia) germinates. The germinating spore or sclerotium produces microscopic threads called a hyphae. A mass of hyphae is called a mycelium (plural is mycelia). These mycelia are sometimes seen as “cotton like” or “cob web like” growths in the turfgrass.
Disease causing hyphae can enter the turfgrass through “wounds” in the tissue (caused by improper mowing, for example). Or, they can enter through the natural openings on the surface of the turf tissue called stomates. The hyphae can grow inside the plant and take plant nutrients, denying the nutrients for your turfgrass. And, the hyphae can reproduce outside the tissue and spread to other plants. Thousands of spores can be found in just 0.25 inches of tissue. During peak discharge times, a fungus may release more than 100,000 spores an hour. Moist tissue aids hyphae in spreading more easily.
For the sake of brevity, I will list some of the more common diseases.
These are foliar diseases:
Brown Patch or Rhizoctonia Blight (Rhizocatonia Solani)
Gray Leaf Spot (Pyricularia Grisea)
Dollar Spot (Sclerotonia Homoeocarpa)
Gray Snow Mold or Typhula Blight (Typhula Incarnata)
Pink Snow Mold and Fusarium Patch (Microdochium Nivale)
Leaf Smuts (Stripe Smut, Ustilago Striiformis, and Flag Smut, Urocystis Agropyri)
Red Thread (Laetisaria Fuciformis, formerly Corticium Fuciforme)
Powdery Mildew (Erysiphe Graminis)
Pink Patch (Limonomyces Roseipellis)
Rust (Puccinia & Uromyces)
White Patch (Melanotus Phillipsii)
Southern Blight or Sclerotium Blight (Sclerotium Rolfsii)
Yellow Patch (Rhizoctonia Cerealis)
These are foliage and/or root diseases:
Curvularia Blight (spp.)
Anthracnose (Colletotrichum Graminicolaand Glomerella Gramincola)
Downy Mildew or Yellow Tuft (Sclerophthora Macrospora)
Drechslera Leaf (spp. formerly known as Helminthosporium)
Fusarium Diseases (Crown and Root Rot)
Necrotic Ring Spot (Leptoshaerea Korrae, formerly known as Fusarium Blight)
Spring Dead Spot (Leptoshaeria Narmari)
Pythium Blight, Cottony Blight, GreasySpot (spp.)
Take All Patch (Gaeumannomyces Gramminis, formerly known as Ophiobolus Patch)
These are some other diseases and disorders:
White Leaf of Bermudagrass (Spiroplasma Citri)
Fairy Ring (Several Soil Inhabiting Fungi)
St. Augustinegrass Decline Virus (SADV– Panicum Mosaic Virus)
Slime Mold (Mucilago Crustacea, Physarum& Fuligo)
I don’t want to get into the various hosts, symptoms, favorable conditions and control strategies for each of these diseases. That will take forever. You’ll have to wait for the book. In fact, there have been many books written just on these diseases. But, before I move on, I’d like to say a few words about NEMATODES. These are basically roundworms. Depending on the species, a nematode may be beneficial or detrimental to plant health. From agriculture and horticulture perspectives, the two categories of nematodes are the predatory ones, which will kill garden pests like cutworms, and the pest nematodes, like the root-knot nematode, which attacks plants, and includes those nematodes that act as a vector, spreading viruses between plants.
Disease control and diagnosis:
In order for a disease to take hold in your turfgrass, three crucial factors must be present. These three conditions are commonly referred to as the “Disease Triangle”. Before you can attack and hopefully control diseases, turfgrass warriors must have an understanding of the disease triangle.
The bottom line with regard to the disease triangle (I know this is a Venn diagram, but, work with me here.) concept is that if any one of the three factors or conditions are missing, disease development will not happen. Please see below:
Here are some simple examples. If you have Tall Fescue grass, you will probably NOT be susceptible to Spring Dead Spot – since Spring Dead Spot only occurs in Bermudagrass. Therefore, you do not have a susceptible host. If there are no pathogens present because you only use disease free soil or sprigs, one of these conditions, the pathogen piece, would be missing. Finally, if you are aware of, or are able to manage some of, your environmental circumstances (including cultural practices), like being aware of the weather, or managing your watering (e.g. most turfgrass diseases need at least 12 hours of moisture before the turfgrass can be penetrated), you are eliminating the conducive environment piece.
The primary method of attacking turf diseases is using fungicides. Much like herbicides, there are two types of fungicides: contact and systemic. Contact fungicides are sprayed on the fungus and inhibit its growth. Contact fungicides will not kill the fungus already in a plant. Systemic fungicides are taken up by the fungus and are effective against fungi that are already in the plant.
If you really want to attempt a proper identification and diagnosis of a turfgrass disease, you must consider these four basic steps: 1. You must correctly identify the turfgrass you have, 2. You must be able to identify the symptoms of the disease, 3. You must be able to have a handle of the environmental conditions (to the extent you can), and 4. You must be able to recognize the signs of the particular pathogen. This is much more difficult than it sounds; trust me.
Ensuring you know what species of grass you have can be tough, especially since there are about 9,000 varieties. Many pathogens are specific to certain species of turfgrass. Similar to the example I gave above, regarding Tall Fescue and Bermudagrass, knowing exactly what kind of grass you have can eliminate many types of diseases and be a big help in the diagnosis process. NC State has excellent online resources for disease identification.
Steps 2 and 4 are very closely related. You must know the difference between SYMPTOMS and SIGNS. I’m serious. SYMPTOMS are changes in the normal appearance of the grass. Larger symptoms may be brown spots, patches or rings. Smaller symptoms may be lesions on the grass leaves. SIGNS are visual evidence that there is a particular pathogen present. Is there “cotton like” mycelia? Smut, Rust, Powdery Mildew each have a different look. The best time to look for signs is in the morning with dew on the grass. Dry turf often does not easily reveal signs of disease.
And, of course, step 3 is all the stuff I’ve been talking about throughout this blog – climatic conditions and cultural practices. Certain diseases are more aggressive in certain temperatures. Most diseases favor conditions of high moisture, high humidity, overcast skies, low light/shade; in addition to improper mowing, watering and excessive thatch.
Just like our other battle streamers for fighting weeds or pests, this may require some special forces. There are some fungicides that can be obtained over the counter. As always, I urge my troops to use caution, read the label and follow directions. Fertilizers, pesticides, herbicides and FUNGICIDES are nothing to take lightly, or try to make in your basement.
Don’t guess. If you need help, give me a shout; or, I can refer you to an expert closer to you. Don’t mess around with this.
07/22/14
Here's an addendum to my post (above) regarding turfgrass diseases. I got a call from Jack. Jack is a customer in the Del Ray area of Alexandria, Virginia. I did his lawn last year. You can see pictures of his lawn in my blog post "Lawns we are working on..." Jack calls me and says, "My Lawn is dying and you gotta come see it!" So I screeched out of my driveway with the turf-mobile and went over to Jack's house. (Maybe I should get some sort of flashing light for the roof of my truck.) Here's some pictures:
Jack's lawn was not doing well. Immediately, I was able to make a diagnosis. Jack's lawn had Brown Patch or Rhizoctonia Blight (Rhizocatonia Solani).
Jack didn't believe me. So, I took a sod sample. This is different from a soil sample. A sod sample is basically an inverted circular and cone shaped cut into the turf, about 8 inches in diameter and 8 inches down.
I shipped that sample to the lab at NC State University. I mentioned above that NC State has some pretty good resources for online turf disease diagnosis. Well, they also have the nation's foremost lab for turfgrass disease diagnosis. But you got to send them sod from the infected area, not just soil.
The lab verified my initial diagnosis - brown patch. How did this happen? Well, I started asking Jack alot of questions. Most of the questions centered around Jack's management practices. Especially his management practices AFTER he was provided my report on what needed to be done to his lawn. My investigation revealed that Jack had been watering too much and he had made an unauthorized application of fertilizer. In fact, Jack had no idea about the fertilizer he put down. Apparently he mixed together a few bags of remnant, old fertilizer he had sitting around his garage. Jack was sufficiently counseled and sent on his way. The good news is, I was able to "prescribe" a good fungicide that could correct the situation. Jack, go forth and sin no more.
07/23/14
I saw Jack after this last post. He and his wife are getting ready to retire to Arizona. He sent me a picture of his future lawn.....well, yard, really.
This is one way to ensure you never have another turfgrass disease!
This is the time of year when lots of folks ask me about WEEDS. I discussed weeds and some weed treatments in a few earlier blog posts, mostly in response to some questions. Here, I want to “set the record straight.” I want to provide some of my thoughts and other information concerning turfgrass weeds.
Uniformity in our lawns is usually what we strive for. Weeds disrupt that uniformity. Weeds also compete with our lawns and playing fields for water, nutrients, light and space.
How do we define what a weed is? A weed is basically a plant growing out of place or where it is not wanted. A few sprigs of some nice warm weather turfgrass popping into your beautiful cool season turfgrass lawn (or vice versa) could be considered a weed. Like bentgrass growing in a stand of Kentucky bluegrass. That could be as disrupting as dandelions or thistles.
A friend of mine, who has a great deal of farming experience in the midwest, once said to me, "A beautiful rose in a field of wheat is a weed."
WEED ECOLOGY
Before developing a weed treatment regimen, let’s look at the ecology of weeds. Weeds have a unique ability to grow in a wide range of habitats and conditions. Weeds almost always possess one or more of the following traits: prolific seed production, rapid establishment, they have either rhizomes or bulbs, and they have long term seed survival. Seeds are the primary manner in which weeds disperse. Many are very abundant seed producers.
The top 6 inches of soil can contain as many as 13,000 weed seeds per cubic foot. And, one study showed how weed seed could still germinate after being in the soil for some 80 years.
Just like any other plant, weeds are influenced by climate factors. Temperature has the most effect. Moisture is the second most common effect. And, the absence or presence of light may impact weed growth. Factors with regard to your soil can also have an impact; pH level, nutrient levels, oxygen content, etc. Some other factors like mowing too low, severely dethatching in the spring, or light irrigation can have an influence. The grass seed you use can have an influence too; make sure the seed has a very low percentage of crop seed or weed seed content. Sanitary practices – like washing your equipment after use can have an influence as well.
If you have weeds, see if any of your management or cultural practices are promoting weed growth before you commence chemical, biological or nuclear warfare. There may be some simple corrective actions to take before you nuke your lawn.
There are two types of turfgrass weeds: grass like or broadleaf. As I mentioned on one of my first posts – grasses are monocots; broadleaf weeds are dicots. Weeds can also be categorized by their life cycles: annuals, biennials or perennials. Annuals complete their life cycle in one growing season, within a year. Annuals that begin in the spring and complete their cycle in the fall are summer annuals. The ones that start in the fall and complete their cycle in the spring are winter annuals.
Biennials require two growing seasons to complete their cycle; the first year they establish themselves vegetatively, the second year they form flowers, set seeds and die. Perennials live for three or more years. Strategies for controlling various weeds are determined by what type of weeds they are.
As I’ve said before – the best way to control weeds is to have a thick, healthy stand of turfgrass, by utilizing proper cultural and management practices. Many weed species are not that “competitive” with thick, healthy turfgrass. When I’m starting from scratch with one of my clients, my first step is to try to get a thick stand of grass growing. I worry about weeds later. Remember, growing a beautiful stand and eliminating weeds can take several growing seasons – it does not happen overnight. You really need to establish a “strategy” or a “program”.
Anyway, I digress…. One way to control weeds is biological control. That’s using the weed’s natural antagonists to control the weed. This is a pretty scientific and extreme method and is probably out of reach for the average homeowner. Besides, this is an area of turfgrass management that needs quite a bit more research to be done – especially for residential use.
Chemical control is something with which we are more familiar. This is the use of herbicides. Herbicides kill or inhibit the growth of plants. Although there are over 180 different types of herbicides; for turfgrass, we only need to consider a few.
Herbicides that target specific weeds are called selective herbicides. Herbicides that kill all plants they come in contact with are nonselective herbicides. Herbicides that kill only the part of the plants with which they come in contact are called contact herbicides.
Herbicides that are absorbed by the roots or shoots and are then translocated within the plant are systemic herbicides. Systemic herbicides are very good at controlling perennial weeds since they kill the underground parts of the plant. In another post, I talked about glyphosate (Commercial Name: “RoundUp”). Glyphosate is a systemic, nonselective herbicide.
Herbicides applied prior to planting or sodding are called preplant herbicides. Preplant herbicides for turfgrass usually involve fumigation with ethyl bromide. Also another method the average homeowner does not want to attempt. You want to try to put a huge tarp over your entire lawn and pump a carcinogen and a reproductive toxin under it? I recommend a different course of action.
Herbicides applied prior to weed emergence are called preemergence herbicides. These form a chemical barrier that when the weed seeds start to germinate and come in contact with the chemical barrier, they die. Preemergents are ineffective if the weeds are already growing. A good preemergent should not hurt established turfgrass. Read the label and look for: benefin, bensulide or DCPA.
Postemergence herbicides are applied after weeds have emerged or started growing. These are used to control broadleaf and perennial grass weeds. Sometimes these are used to control annual grasses. Converse to preemergent herbicides, postemergent herbicides do not control weeds prior to their emergence from the soil. Look on your postemergent labels for contents like MSMA, or 2,4-D.
ANNUAL GRASSES
Annual grasses can be controlled by either post or preemergent herbicides, although preemergent is best. As I discussed in an earlier post, put your preemergents down early – when the soil temperatures at a 2 inch depth is no more than 55 degrees F. Remember, when you do that, you have just put down a chemical barrier. That barrier will remain in place for 6 to 12 weeks. That will prevent ANYTHING – even good grass seed – from growing.
Postemergence herbicides on annual grasses are most effective when the weeds are in early stages of growth. So, this should be rather “early” in the season too. In many cases, two applications may be necessary. Space out those applications at least 10 to 14 days. Postemergence has its issues: there may be a need for multiple applications, dying annual grasses can be unsightly in your turfgrass, and, postemergent herbicides may discolor and weaken desirable turfgrass.
PERENNIAL GRASSES
These are really difficult to control. Much of the time they cannot be selectively controlled. The physiology and anatomy of perennial grass weeds and desirable turfgrasses are very similar. What kills one could kill the other. Spot treatment of perennial weed grasses is the key – trying to avoid touching the nearby desirable turfgrass with the herbicide - or as little as possible.
BROADLEAFS
These are the most common in turfgrass. Look for these chemicals on the label; 2,4-D, mecoprop and dicamba. These are systemic in nature. If you have at least two of these three chemicals on the label, you’ll be okay. If you see all three, you're in great shape. Now, be careful. These can harm surrounding vegetables, flowers, trees or shrubs. Dicamba is very mobile in the soil. Broadleafs are best controlled with postemergent herbicides. Some warm season turfs are sensitive to 2,4-D and dicamba – like St. Augustine and Bermuda.
GRASSLIKE WEEDS
Repeated applications of 2,4-D and Dicamba will provide fair to good control.
OTHER CONSIDERATIONS
Always read the label and comply with the instructions.
If using a postemergent, treat weeds at the early stages of growth and the weeds should be actively growing and not under drought or temperature stress. Air temperature should be between 65 and 85 degrees F.
Do not mow for 3 to 4 days prior to application so maximum weed topgrowth can come in contact with the herbicide.
Postemergents should stay on the foliage for at least several hours for best results. Avoid watering for at least 8 hours, ideally 24 hours, after application. Do not apply if rain is in the weather forecast within 24 hours. Delay mowing after application as long as possible.
Do not apply in windy conditions.
When using granular herbicides for broadleaf control, you will get best results if the weed is moist. You want the herbicide to “stick” to the weeds. Do not allow any traffic on the treated area for 8 to 10 hours after application.
Be patient if you see little or no results. Several days to three weeks may pass before there are any signs of success.
In many cases, newly seeded or sprigged areas are not tolerant of herbicides. Make sure you’ve mowed (using the one third/two third rule) at least three times prior to application to new areas.
Do not apply postemergents to warm season turfs as they break winter dormancy. Wait until the warm season grasses are completely out of dormancy.
After attacking broadleafs, wait 4 to 6 weeks before seeding or sprigging.
Grass clippings from recently treated herbicides should NOT be used as mulch around trees, shrubs, vegetables or flowers. Clippings collected after the turf has been mowed 3 to 4 times should be okay.
MY STRATEGY FOR WEEDS
I put my (granular) preemergent down rather early. Since I live in the mid-Atlantic region (the transition zone), I go for early to mid March. Now, this has been a very cool spring this year. But, my early approach continues to work. That usually is about a 90% solution. Some weeds still manage to pop up.
So, later, in mid April or early May, I put down my (granular)postemergent herbicide. That handles most of the ones that persist. Let’s say that’s now at a 95% to 98% solution.
Then I “spot treat” the “one-sies and two-sies” that still manage to foil my efforts with a (liquid) postemergent. I have a one gallon, pump action sprayer. It even has a strap on it so I can lug it around the yard. I spray each weed, in the center of mass with a steady stream for two or three seconds.
I realize the spot treatment phase of the operation may not be feasible for those of you with larger lawns. There are larger supplies of herbicides for larger lawns and you can get real serious with applicator equipment that can be towed behind a tractor or are self propelled, walk behind types. For example, I have a broadcast spreader that I can tow behind my lawn tractor.
Each year (or growing season) can be different. This year its chickweed. My chickweed survived every assault, until I spot treated it with my sprayer. It took at least two to three weeks to see any effect. Once it was dead, I tilled it under and planted some grass seed. That area looks beautiful now.
I recommend to my clients to do NOTHING (herbicides, pesticides or fertilizing) once the soil/air temperatures start to climb – like mid May or definitely by Memorial Day – JUST STOP; reconsolidate in your current fighting position. If you still have a weed problem by the end of May, live to fight another day. Focus on mowing and (perhaps – especially depending on rain) watering over the summer. Start planning subsequent operations for the fall.