Hey There, Turf-heads! It’s been a while!
Early in the month, a faithful follower, BigD, wrote:
Early in the month, a faithful follower, BigD, wrote:
This past Saturday morning, while running errands for the family (not just my wife, but my daughter…WTF?), I had occasion to listen to a popular talk show host on the AM airwaves. I concede that this person has a few key strengths (indoor horticulture, annuals, perennials) in the broader field of horticulture, but his understanding of the SCIENCE of pesticides, especially herbicides, is woefully inadequate. Every summer, right on cue, this goofball says, “Summer weeds have hardened off so much, you really can’tkill them with herbicides!” What a load of crap! He proclaims this for both nutsedge and the entire collection of broadleaf herbicides. He’s dead wrong!
Before I skewer him on his abject stupidity in this specialty area, I’ll try to give him the benefit of the doubt. I’m a fair guy…even-tempered…open-minded—for an Irishman (50%). Maybe he’s thinking about those huge mats of crabgrass, two feet in diameter, or a hefty clump of goosegrass (aka “silver crabgrass”)(below left). Or maybe it’s an established area of deep-rooted black medic (below right). [By the way, the photo of black medic also has some white dutch clover in the photo–both are legumes–and both are tough weeds, but black medic is tougher!] These tough weeds become quite noticeable in late summer because they love the heat and they get very large. Herbicides have their limits–they kill small seedlings easy but an established monster weed won’t be controlled. There are no “selective” POST herbicides that will kill these tough weeds with only one application, this time of year. A “selective” herbicide means it will kill weeds but not grass (if used properly). But a non-selective herbicide, glyphosate (Roundup), CAN kill all these weeds, along with the turf!. STOP HERE! It’ll take at least two applications of glyphosate to kill established black medic. It will take at least 3 applications of common retail broadleaf weed killers to kill established black medic.
Herbicides used in turfgrass work by preventing weed seeds from developing (PREEMERGENCE or “PRE”) or killing established weeds after they are emerged (POSTEMERGENCE or “POST”). Every single herbicide used in turf can injure turf if over-applied, and most herbicides can even kill turf if horribly over-applied. There are “easy-to-control” weeds and there are “tough-to-control” weeds for every product used in your lawn and landscape. For example, dandelion is an “easy” weed for the multitude of broadleaf weed herbicides, while wild violet is a tough weed (3 applications required). Crabgrass is an easy weed for PREEN to prevent but nightshade is a tough weed for this product. PRE herbicides cannot control weeds beyond the seedling germination stage and POST herbicides work best on weeds less than 4 inches tall/wide. So our talk show host is only partially right about why herbicides might disappoint when applied in late summer. THE WEEDS ARE TOO FREAKIN’ BIG! They aren’t “tougher!”
Halosulfuron, the best herbicide on the face of the earth for control of nutsedge, is sold under “at least 3 different names, such as PROSEDGE, SEDGEHAMMER, and NUTBUSTER. It still works GREAT right now! But the host of this show will tell you otherwise. [SIDEBAR: i did 75% of the development research for this herbicide while employed by Monsanto in the mid- to late-80’s, and it was introduced as MANAGE herbicide. I know WTF I’m talking about!] The broadleaf herbicides (no fewer than half a dozen) will still control weeds 4 inches tall if you apply them now, as long as it’s an easy-to-control weed.
In summation: this guy doesn’t know crap about herbicides and weed control.
There are two ddifferent guys on two different stations that over-promote their proprietary compost blends. Not just for turf, but for ALL lawn and landscape woes. Compost is wonderful as a topdressing in turf, or when incorporated into the native soil when you’re establishing new beds. I don’t recommend it as a mulch because it becomes very powdery when it dries out. Heavy rains or heavy irrigation can wash compost downslope quite easily.
My beef with these two hosts is that they OVER PROMOTE the nutrient content of compost, and one says you don’t need to fertilize your lawn all season long! This is just pure crap.
The vast majority of our soils in St. Louis are typically adequate in phosphorous (P) and potassium (K) thus good turf management generally comes down to proper management of nitrogen (N). Fertilizer values for these there macronutrients are provided in the order of N-P-K. Compost typically 1-1-1. Furthermore, the nitrogen in the compost is very slowly released, in YEARS. Not days, not months, but YEARS. It may take 3 years for all the nitrogen in compost to be made available for use by plants. Compost usually has about 1% phosphorous, but it is essentially unavailable for several years. Finally, compost has about 1% potassium and it is readily available.
Let’s get back to the N, because good turf is all about the N! Healthy cool season turf in the transition zone needs between 2.5 and 4 lbs of N per season, per 1,000 sq ft. By simple math there is no way a single application of compost will provide you with a decent looking sward. We always want to limit our nitrogen to only 1 lb of actual N per 1,000 sq ft in a single application. With compost having only 1% nitrogen, that’s 100 lbs of compost per 1,000 sq ft. That’s certainly “doable” but a lot of work.
There’s nothing wrong with adding compost to the lawn, especially if it’s applied as a top-dressing after heavy aeration and seeding. There are billions upon billions of beneficial microbes in compost which serve to break down thatch, improve soil structure, combat pathogenic fungi, and improve aeration.
In summation: these guys should stop over-promoting compost as an adequate source of nitrogen.
Remember folks, the month of September makes or breaks the turf studs from the turf duds. If you aspire for a great lawn, work hard now through mid-October.
Mid-June in the Transition Zone is the right time to kill the newest batch of grubs that feed on grass roots. There at nearly a dozen different species, but the dominant beetles that make grubs in STL are the chafers and the Japanese beetles. The B-52 sized June bug is less common, but when you come across a June bug grub, it’s freaky huge! You’ll scream like a sissy. If you’re unsure what a grub worm looks like, just Google it. [Are you shittin’ me? Don’t know what one looks like? Oh wait, I forgot that most millennials spent all their time in the basement playing video games!]
Eggs hatch and the larvae will eat the roots of turf. Egg hatch in STL is usually complete for all the species in early to mid-August. Grubworms go through a series of instar stages (molts) getting larger with each molt. Insecticides applied right now do a better job of killing the little babies while they’re small. We apply our systemic insecticides in mid-June so that the turfgrass has plenty of time to absorb and translocate the insecticide throughout the plant. Grub bites root—grub gets upset tummy—grub dies! Contact insecticides area applied in mid-August—because they don’t need to be taken up by the turf roots. Mr. Grub just digs and eats—insecticide washes over the poor baby—grub baby dies!
I will tell you now that the systemic products are more effective than the contact products for killing grubs. In dry years when the grubs are deeper in the soil, the contact products can be diluted in soil profile, and thus, less effective overall. They work great when the grubs are closer to the soil surface. On the other hand, contact products also kill fleas, ticks, spiders, crane flies, crickets, and a host of other bugs.
Grub damage tends to be patchy. Even when grubs are heavy in area, there will be individual clumps of surviving fescue plants—think “hair plugs for men!” This picture below captures the essence of a fescue lawn with grub damage. Note the relatively large patch of mostly dead grass. But note that there are several hundred individual clumps of grass (mostly fescue) that have survived! Some grasses contain an “endophyte” fungus that lives in the roots of infected plants. Grubs don’t like the alkaloids (natural insecticide) that the endophyte produces. Therefore we get this type of response–very clumpy. Kinda like “hair plugs for men!” Grubs don’t destroy 100% of the turf in the patches they infest.
Healthy, irrigated turf in STL can usually handle 10 or so grubs per sq ft, but crappy turf can’t. Weak turf might only tolerate 3 to 5 grubs/sq ft. When grub populations are extreme you can literally pick up turf like a throw carpet! I’ve seen this only once in my career, and the grubs were massive June bug grubs!
Below are photos of the 4 most dominant products sold for grub control. Be careful to use the right dose for grubs! While the bag may state, “Treats up to 12,500 sq ft” that’s for the surface-feeding insects. I’ll discuss their active ingredients, pros and cons, and cost from my local Home Depot (Lowe’s sucks, by the way).
Spectracide Triazicide Insect Killer: Contact Insecticide (cyhalothrin). Apply early to mid-August for grubs, but anytime for fleas and ticks. A 20 lb bag costs $13 and treats 16,600 sq ft. $0.78 per 1,000 sq ft.
Roundup Bug Destroyer: Systemic Insecticide plus Contact Insecticide (chlorantraniliprole plus bifenthrin). Apply early to mid-June. A 10 lb bag costs $17 and treats 2,500 sq ft. $6.80 per 1,000 sq ft.
Scott’s Grub Ex: Systemic Insecticide (chlorantraniliprole). Apply early to mid-June. A 14.5 lb bag costs $21 and treats 5,000 sq ft. $4.20 per 1,000 sq ft.
Bio Advanced Grub Killer Plus: Contact Insecticide (trichlorfon). Apply to mid-August. A 10 lb bag costs $19 and treats 5,000 sq ft. $3.80 per 1,00 sq ft.
Ortho Bug Be Gone: picture not shown. Bifenthrin contact insecticide. Special sale–10 lb bag for only $7.00. Treats 2,500 sq ft. $2.80 per 1,000 sq ft.
Professional Blends on Fertilizer Granules: Many professional LCO’s use non-nitrogen fertilizers with systemic insecticides (typically imidacloprid or acelepryn) at the recommended application time
If I were hosting a garden party, I’d purchase Triazicide and apply it a week ahead of time, to cleanse the area of surface pests. But for grubs, I recommend the systemic insecticides.
No get off your arse and apply your insecticide now!
Brown patch is caused by the ubiquitous pathogen, Rhizoctonia solani, and it infects virtually every species of turf in the US. Tall fescue and turf-type fescue is far more susceptible than Kentucky bluegrass, but the latter gets it, too. In zoysiagrass this same organism causes zoysia patch disease. For you golfers, blame those ugly summer greens on brown patch! Seedling turf is extremely susceptible to brown patch, which is why most experts discourage spring seeding.
The fungi lives on decaying organic matter in our lawns, at the interface of organic matter and the soil surface. It rears its pathogenic side during prolonged periods of hot and humid weather, especially during dry spells. You can bet your bum that when the dew points and the night time lows are in the 70’s, we’ll have an outbreak. For photos, just Google “brown patch in fescue turf” for more pics than you can handle. I’ll tell you right now that 95% of disease in Midwestern transition zone turf is brown patch.
There are numerous cultural practices that you should employ in an attempt to minimize the impact of brown patch on your lawn, but to really control this disease, you’ll need the help of fungicides. First, let’s talk about those things you can manage from a cultural perspective.
It’s important to use the right product for control of brown patch, which is azoxystrobin (I pronounce it “a-ZOX-e-stroh-bin”, but I’m not the sharpest tool in the shed!). A disease program MUST contain this active ingredient, proven by universities to be the best single fungicide for brown patch. However, it should not be used alone! The best companion product is propiconazole (pro-PEE-con-a-zole).
Fungicides aren’t cheap. Actually, they are very expensive, especially considering you need to apply them every 3 to 4 weeks during the dog days. No matter the product you use, read the label and follow the coverage recommendation for brown patch. If you stretch it too far you’re wasting your time and money. Just burn those bills on the BBQ…or better yet, send them to me!
There’s a commercial product available at professional turf outlets called Headway G. A 30 lb bag covers 10,000 sq ft on a preventative basis, but only 5,000 sq ft on a curative basis. If you’re just now reading this (mid-June-2018), your first application is in the CURATIVE dose rate. When I was in the business we’d instruct our Sward Masters to make their first preventative application a full week ahead of the prolonged 90 F degree weather forecast. If we get a wonderful clearing cold front that drops our temps and humidity, stretch it to the 4 week interval.
The photos below show the Scott’s product containing azoxystrobin (DiseaseEX) and the Bayer product with propiconazole. I’d recommend you buy both for your first shot. Apply them both, individually of course, if your lawn is suffering terribly. Each bag covers 5,000 sq ft. Used alone, the manufacturers suggest applying every 2 weeks in miserable weather, every 4 weeks otherwise. But that’s used alone.
After application water well, in the AM. Then in 3 weeks apply azoxystrobin again. Three weeks later apply propiconazole. Repeat until the cool weather arrives (crap, that’ll be October!). And oh, by the way, don’t count on 100% control! Ain’t gonna happen. Be happy with 80% control.
Let me know if you give these products a go!
I grew tired of watching some of my landscape ornamentals get hit with powdery mildew every summer. A buddy of mine with a lot of pathology experience (pun intended) suggested I try the fungicide tebuconazole as a preventative root drench.
So, I found this product on the shelf, Bayer Advanced All in One Rose and Flower Care. In addition to fungicide it has a systemic insecticide (imidacloprid) and some fertilizer (9–14-9). I was also sick of black spot on my roses, which this controls. The insecticide controls feeding adult Japanese beetles, a huge plus, aphids, scales, leaf miners and a host of other pests.
So I bought it and put it to the test. The general directions are 2 fluid ounces per plant, or 2 fluid ounces per 12 sq ft of general mass plantings, as a drench in 1 qt to 1 gal of water.
Back in early May I treated my roses, a 16 ft tall native flowering dogwood, ‘Mrs Moon’ lungwort, two peonies,garden phlox, woodland phlox and a mass planting of Monarda (beebalm). Interesting that every beebalm in my bed was advertised as resistant to powdery mildew! Total crap in St. Louis! I’m impressed! Especially with the lack of mildew in my Monarda bed! Directions say treat every 6 weeks, which I intend to do, because we’ve got another two months of mildew enhancing weather!
Hey folks, when it comes to taking care of the yard, aka “the sward”, the absolute very first thing a do-it-yourself (DIY) lawn tender MUST know is how many thousand square feet of actual TURF one has. Back to the sward comment…a crappy yard is not a sward! Only a beautiful yard, one that creates envy, can be called a sward!
This is a serious matter, because success or failure in your lawn care practice is based upon the PROPER DOSE. It’s important for fungicides, herbicides, insecticides and especially fertilizers. Think about it for a second. If you apply a bag of insecticide designed for 5,000 sq ft over your 12,000 sq ft lawn, do you think it’ll work properly? Hell no! And when you apply a 50 lb bag of fertilizer with a 24-8-12 formulation over a 5,000 sq ft lawn, would you expect success? The aforementioned bag of fertilizer has 12 lbs of actual nitrogen in it (50 lbs x 0.24 = 12), and thus would cover 12,000 sq ft of turf in the fall. Put that much nitrogen on a tiny yard and you’ll have a dead lawn after about a month of summer heat.
Back in 2012 when I was with THE Turf Plan, I penned a nice blog about this. Rather than regurgitate it, I’ll recycle it! Go to this link on THE Turf Plan website and read up: How Large is Your Sward.
You needed get carried away but get within 10% accuracy. Don’t be a dumb ass! Figure it out.
Success will follow!
It’s mid-March so the lawn care operators (LCOs) are applying their Round 1 product, consisting of fertilizer plus crabgrass preemergent herbicide. LCOs start early because it’s better to be early than late! However, any company applying a crabgrass product now MUST also apply a SECOND SHOT of crabgrass preemergent (late April to mid-May). The exception to this rule is for superb lawns, where the healthy sward is so thick and lush that crabgrass seeds have no chance to contact the soil surface. BTW, for the do-it-yourselfer it’s too early. You can wait until at least April 1st.
Nothing chaps my ass like seeing these application notifications where the company made an application over a crap ton of leaves and debris! This is usually where the damn crabgrass is going to be bad! Your lawn care company should have given you a heads up a few weeks in advance, saying something to the tune of, “Dear Customer, we’ll be applying your first round of fertilizer and crabgrass product in mid-March. Please do your best to get the leaves and organic litter cleaned up, so that our product can do its job!” This is why THE Turf Plan is so successful, because they send you timely emails–educational and informative (check out www.theturfplan.com). Your local LCOs will do a far superior job than the national chains.
If you have crabgrass in your lawn, FIRE your LCO! Right now! Crabgrass preemergent herbicides are extremely effective, so there is zero excuse for crabgrass in your lawn! This is especially true if you’ve given your LCO more than one season of business. To further reinforce this point there are new products that can be used postemergent (after the weed comes up), meaning your LCO can clean up any mistakes in mid-May.
There 3 common preemergent crabgrass herbicides that are combined with fertilizer products. The absolute best is dithiopyr (Dimension®), the second best is prodiamine (Barricade®), and the really sucky one is pendimethalin (Pendulum®, favored by that national brand!). I rank Dimension as #1 because it will actually kill small (1/2 inch or less) emerged crabgrass. If you’re a week or so late with your first shot, Dimension can kill those early emerging crabgrass plants. Look the bag over carefully and avoid pendimethalin–unless you’re sure you’ll apply that second shot. But be warned, products with pendimethalin usually have WAY TOO MUCH nitrogen (anything over 18%). You don’t want to apply a lot of nitrogen in the spring.
Crabgrass will emerge when soil surface temps reach 55F for about 3 nights in a row. If you live near agricultural areas, when the farmers start planting corn, you need to apply your first shot of crabgrass preventer. Suburbanites can use a phenological indicator, the forsythia bloom, as a guide. However, it’s not the BEGINNING of the forsythia bloom, it’s towards the END of the forsythia bloom that is more accurate (wait for that third week of yellow).
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