Battle in the blades

Although weather patterns have been more normal this year than last, turf diseases and pests still remain a challenge to lawn and landscape operators.

While landscape professionals may have been scratching their heads over last year’s odd weather, wondering what happened to spring when it seemed that winter transitioned straight into summer, this year has been more normal. In fact, it’s been a little bit more moist than normal, which in some cases has contributed to certain turf diseases having a field day.

Red thread has been a major problem on cool-season turf in Virgina.

The cool temperatures and moisture have been great for cool-season grass growth in Virginia and other parts of the Transition Zone. But cool-season diseases such as dollar spot, red thread, pink patch and leaf spot have also been in their glory. Dollar spot and leaf spot are showing up on both warm- and cool-season grasses. Overall, Michael Goatley of the Virginia Cooperative Extension says it has been a very high pressure disease year.

“We have even seen pythium blight on bermuda already this year,” Goatley says. “People tend to think of pythium as being a warm, wet weather disease on cool-season grass, but during slower times for bermuda when it’s not actively growing, we’ve had it show up on intramural fields on (Virginia Tech’s) campus.”

Goatley says the large patch outbreaks on bermuda and zoysia in particular were also significant last spring due to the extreme cool and wet conditions. He calls those diseases the “cool-season versions of brown patch.”

The two diseases Goatley says have exploded this year on cool-season turf are dollar spot and red thread/pink patch. While golf course superintendents can’t really live with the damage dollar spot does to greens, lawn care professionals can “grin and bear it” on taller turf, he says.

“Both of these diseases quite often can be handled just by paying attention to your fertilization program. A lot of times, they’re really severe, and the reason is because the turf quite often is probably lacking in nitrogen nutrition,” he says. “We typically think of those diseases as ones that hit the hardest on grass that hasn’t been well fertilized. But my yard has been properly fertilized and I still have pressure from pink patch, red thread and dollar spot. Still, proper fertilization helps us stay away from applying a lot of fungicides. The caveat to that is you can’t be too aggressive with nitrogen because that sets you up for brown patch outbreaks that will show up when temperatures warm up and a little bit of drought stress sets in.”

Goatley says that lawn professionals work with their local extension office to make sure they identify diseases properly; otherwise, they could take the exact opposite action needed to address the problem. As far as turf pests go, Goatley says he hasn’t seen anything unusual this season other than white grubs, which year-in and year-out are the biggest nuisance on cool-season grasses. Still, he says there have been few reports on grub activity this year due to the mild and moist conditions. If it stays cool and wet, Goatley predicts that most cool-season grasses probably won’t show the type of stress symptomatic of hotter, drier conditions.

“However, we are cautioning people not to fall asleep at the wheel,” he says. “Pay attention as you’re doing your scouting. If you suspect there are grubs, I think the problems could be even greater this year because, with all the rain we’ve been getting, all the root systems on most of these grasses probably aren’t as deep as they typically are in another year where the turf is allowed to dry out.”

Goatley’s recommendations to new landscape contractors and lawn care operators when tackling these diseases and pests is to understand that the learning is more than just looking at field research plots when the Extension offers its field days.

“The learning comes from listening to their peers who are fighting the same battles they are and getting to know these people,” he says. “In many cases, especially if you’re not a competitor right down the street but maybe 60 miles away, they feel comfortable talking about and sharing how they deal with these issues.”

Dollar spot has hit the Virginia area hard this year on cool-season turf.

In Texas, turf diseases and pests tend to be location-dependent. Conditions differ greatly, from East Texas that might see 50 inches of rain a year to El Paso, which might get eight inches. In North Texas, the growing season is typically five and a half months for warm-season grasses, whereas the south’s is 11 months. With all that considered, one of the common diseases seen is rhizoctonia.

“This is the No. 1 issue in lawns here, which are predominantly St. Augustine grass,” says Ben Wherley of the Department of Crop and Soil Sciences at Texas A&M. “It starts to develop in October in Central Texas and hangs around until May when we get some 90-degree days and the turf becomes active.”

Wherley says take-all patch can be easily remedied through pH management. Texas soils tend to be highly alkaline, so applications of elemental sulphur or acidifying fertilizer are typically recommended. Some natural approaches might include topdressing with peat moss or compost that has an acidifying drench.

Chinch bugs can pose issues in St. Augustine grass and are many times masked as drought stress, Wherley says, when the yellow spots turn brown. Although not as prevalent in lawns, billbugs can also present problems, but a good deal of their damage is caused in sod.

“They get in there and feed in the rhizomes and stolons, which become hollow and begin to deteriorate,” Wherley says. “We’ll get calls from sod producers who say they’re trying to cut their fields and the sod won’t hold together.” Wherley’s No. 1 advice to new lawn care operators is read and understand product labels.

“The labels are law. I tend to be wary giving recommendations because the labels can change, so it’s important to understand what products can and can’t be applied on home lawns.

We have extension bulletins available for landscape contractors and turf managers that will provide recommendations on the most effective products out there.”

For pests like crane flies and billbugs, Kowalewski says following good IPM practices, scouting early and making applications at the first sign of problems. As far as diseases, the main problem won’t be disease through the summer, says Alec Kowalewski, turfgrass specialist at Oregon State University.

It will be heat stress and things related to heat stress. Anthracnose, which is typically the biggest problem lawn operators in the region face, is usually an indicator of stress issues and impacts annual bluegrass. “My advice is to do more frequent irrigation through the summer and raise mower height,” Kowalewski says. “That will make any turf healthier through summer.” L&L

Seeding vs. Sodding

The old seeding vs. sodding debate reminds some of the old “tastes great, less filling” Miller Lite ad campaign: two sides shouting their opinion. Okay, maybe that’s a stretch. There’s not a lot of shouting going on, but there are definitely pros and cons to be heard.

Many times, it comes down to cost. Just ask Tyler Washburn of Outback Landscape in Rexburg, Idaho, who is out in the field every day and seeing what customers prefer.

“We try to sod when we can on a new installation, but a lot of times due to the cost of the project, the homeowner will opt to go with seeding because it’s cheaper,” he says.

The nice thing about sod, Washburn says, is that it’s “instant grass” that experiences less problems with weeds than seeding. Plus, with seeding, you have to wait for the grass to fill in.

“Homeowners prefer seeding from a cost standpoint, but we prefer sod – and most homeowners prefer sod if it fits within their budget.”

Michael Goatley, extension turfgrass specialist with Virginia Tech, agrees that sod offers the instant gratification of instant green and immediate use. But he says that quite often, it doesn’t turn out to be as expensive as a lot of people think after they first experience the “sticker shock” of comparing what it costs to buy a square yard of sod versus a few pounds of seed.

“Sodding gets overlooked because of price, but the benefits in terms of soil stabilization and immediate use and the aesthetic appeal of it certainly has a lot to offer,” Goatley says. “It gives you instant soil stabilization. When I go to any sites where people are looking at any type of slope whatsoever, unless they’re really good at what they’re doing and maybe are going to use some type of mesh material to keep the seed from washing away, I believe their best investment would be sod.”

Goatley says that most people he works with tend to seed from the standpoint of the upfront cost, but he has sensed a subtle shift, especially among construction contractors, toward sod.

“I think they’re realizing the benefits and, instead of worrying about whether anybody is going to water or if it’s going to rain, they’ll make the investment in sod,” he says. “Then, they seem to be able to convince people, ‘Hey, you have that type of system installed, so let’s commit to that and get that thing the moisture it needs.’”

In Texas, the option of seeding doesn’t exist for most warm-season grasses, according to Ben Wherley, assistant professor of physiology and ecology in the Department of Soil and Crop Sciences at Texas A & M University. Among St. Augustine grass, zoysia, buffalograss and bermuda, bermuda is the only one he recommends for seeding. “In the past, buffalo sod had challenges of holding together,” Wherley says. “Landscapers in Texas haven’t liked to lay it down because they said you could only handle it one time when it went from the sod harvester to the pallet. The second time you handled it, it would fall apart. But now there are newer varieties of buffalo out there that almost look like bermuda and block very nicely.”

Like Goatley, Wherley believes sod might be as cost effective as seeding when you look at all the steps that go into seeding.

“It’s initially more costly to sod, say, zoysia, but if you’re doing a large-scale project, by the time you have weeds under control and have managed the lawn to the point where it’s fully established, you may have put nearly as much resources and control products into it where the expense equals sodding it. So we tend to promote sodding if people can do it.”

Seeding zoysia, Wherley says, is a major challenge.

“I have yet to talk with someone who has had a positive experience with it. It’s very slow, and you tend to have challenges with competing weeds.”

The other consideration with seeding vs. sodding in Texas, Wherley says, is water restrictions. A lot of municipalities have been falling under Stage 3, where residents could only water their lawns once every week or two. So they established a 35-day period to get a lawn established.

“In those cases, sodding may be the better choice,” he says.

The author is a freelance writer based in Cleveland.

Photos courtesy of noon turf care; ben wherley; Mike Goatley

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