Mid-June is Grub Control Time

Apply Insecticides Now to Kill Baby Grubs

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.

Grub Damage

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!

Trav

 

 

 

Brown Patch: the big nasty turf spoiler

Rhizoctonia solani…

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.

  1. Keep the blade sharp:  No, I’m not talking about the 7 habits bull crap. Literally. Keep. The. Blade. Sharp. (My daughters tell me this infers extreme emphasis…does it?) Come mid-May, you should be sure to have a brand-new sharpening job on that blade. Buy an extra and always have a sharp one handy.  Don’t go more than 3 months without sharpening your blade (average homeowner).
  2. Keep the deck high:  Mow cool season turf in full sun at maximum height on your mower. 4 inches is better than 3 inches! For cool season turf in good shade, you can mow lower, say 2.5 inches, because you don’t want turf to stay wet from dew, irrigation or rainfall excessively long. If you’re serious about being the beast of turf in your neighborhood, you should have a reasonably new mower, capably of 3.5 or 4 inch mowing heights.
  3. Water in the morning:  All diseases need moisture for the spores to germinate and grow. Watering at night keeps the grass covered in a film of moisture all night long. Thus, more disease.
  4. Bag your clippings in the dog days of summer:  Bagging the diseased-laden grass when the outbreak is bad has been shown to reduce the spread of the disease. When you’re miserable outside so is your turf. I like to tell folks when the heat index is above 90F, your turf isn’t happy. When the heat index is above 100F, your turf is pissed at you…for watering it, fertilizing it, and doing all those things to keep it from going dormant.
  5. Avoid excessive nitrogen in June, July and August:  Points 1 to 4 are important, but my experience shows that 90% of you with terrible brown patch used the wrong fertilizer at the wrong time. Anybody putting traditional, synthetic fertilizer formulations down after mid-May is begging for the disease. You don’t want soft and succulent turf around when the conditions are right. The biggest national brand sells stuff so high in nitrogen it should only be used on zoysiagrass in the summer. Weed-and-Feed formulations are terribly high in nitrogen. They suck! Both for killing weeds and too much N…I’ll save this rant for later this summer. Seriously, cool season turf in St. Louis and the rest of the transition zone should get 75% of its nitrogen in the fall, to support the plant’s natural growth cycle. Using high nitrogen fertilizers in the early spring isn’t a death knell, but your crabgrass product is best with 12% or less nitrogen. Retail stuff sucks, with 24% or more nitrogen in the bag. And retail stuff has a crappy herbicide, too. Your grass will green up wonderfully in the spring if you do most of your fertilizing in the fall. The astute reader is now asking herself, “Well then, what the hell SHOULD I use in the summer?” I love organic nitrogen in the summer, but ONLY for irrigated lawns. I especially like Milorganite (and the knock offs) for irrigated turf, because it has low nitrogen content, all slow release, and a lot of iron. If you’re not irrigating, don’t fertilize after your crabgrass product goes down. Reread that–if you’re NOT irrigating in the summer–DO NOT fertilize in the summer!

Fungicides

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!

Stay Cool!

Trav

 

THIS STUFF WORKS!

Bayer 3 wayI 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!

Stay tuned!

Trav

How Large is Your Sward?

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!

Trav