Some level of snow cover is likely needed for pink snow mold to infect turf.
photo: Matt Giese/Syngenta

August in the northern parts of the United States: warm temperatures, heavy play, exhausted crews, dry turf and humming equipment. Snow mold might not fit with other end-of-summer thoughts. However, for regions with limited play windows, this turf disease warrants serious consideration.

Preventing the spring reveal from becoming a horrifying experience requires foresight. Devoting a small chunk of August to snow mold – yes, it’s possible to use snow and August in the same sentence – can reap big rewards the following spring.

Mid-August is an ideal time to begin snow mold preparations, says Syngenta technical field manager and snow mold guru Matt Giese. In addition to the fact fungicide prices are more attractive, there’s also a technical element associated with preparing early.

“You can kind of reflect back on what worked in previous years,” Giese says. “And if you need to make a change, you will have some time to maybe contemplate that before you need to go out there and mix it up and make the applications, whether you make them in October or November. Things are going to come up during that time of the year, so you’re giving yourself an opportunity to make some changes if necessary.”

Doug Hoeh starts thinking about snow mold even earlier. With five courses supporting 100,000 rounds, the director of golf course maintenance at Treetops Resort in Gaylord, Mich., says getting ahead on coverage negates weather-related pitfalls during the application period.

In most cases, gray snow mold requires at least 60 days of snow cover to infect.
photo: Matt Giese/Syngenta

Treetops’ condensed season runs from late-April to October, and the resort competes with many of Michigan’s 45 other public golf resorts for business. Michigan’s 665 public golf courses ranks second in the nation behind Florida, according to the National Golf Foundation. Conditioning can enhance and damage reputations in the crowded golf marketplace, and Hoeh learned early in his career snow mold is a disease not to mess around with.

“All other diseases, whether it be brown patch, a little anthracnose or dollar spot, you can see them, you can cure them, you can prevent them,” he says. “When it comes to snow mold, once we get snow usually in November, we don’t’ lose it until April. I can’t apply or go out and do anything so I have to get it right for the first time.”

July seems like a curious time to review spray notes from the previous fall and meet with industry partners about snow mold. But Hoeh devotes time during the second half of the month to planning snow mold applications. The resort’s golf terrain includes 20 acres of greens, 24 acres of tees and 130 acres of fairways. Every square foot of the three surfaces gets treated for snow mold.

photo: Matt Giese/Syngenta

“Every year we try to do something different to see if it’s easier for us to spray and if we get the results,” Hoeh says. “Having this much acreage to spray, we are kind of at a luxury. It’s not a big deal for us to mix a tank and go spray nine greens and nine tees with a different product on a different course just to see the results we get out of that. We will compare our notes, we will compare cost and then sit down.”

Hoeh allows Michigan State University to perform snow mold trials on Treetops’ turf, and the presence of five courses allows him to test new products on areas with high disease pressure. After Contend received EPA approval last fall, he sprayed the fungicide on a problematic fairway. Contend combines four active ingredients, including Solatenol, a new active ingredient for turf. Hoeh observed clean results on the fairway, and he will likely increase his Contend usage this fall.

“I like to test products in the field and in different spots,” he says. “I know what the high-pressure areas are and I want to see what a product does. I will throw it in a high-pressure area. We have certain areas where we always get pink snow mold. We have certain areas where we get gray snow mold, and we have certain areas where we get both. I will throw it in different areas and try it. Yeah, if you are going to walk in and tell me your product is the best, I’m going to throw it at the worst spot I got and we will look at it together.”

Hoeh combines a thorough chemical approach with reliable cultural practices. A limited season means aerification occurs around the time each course closes in mid-October. Treetops’ greens are topdressed in the fall and fertilization ends in early September. For courses in the snow mold region, generally the upper half of the United States, Giese recommends avoiding lush turf conditions entering winter. Mild fall temperatures allowing golf seasons to stretch into November and December in parts of the Northeast, Mid-Atlantic and Midwest present challenges because of turf growth and continued disease pressure. Improving surface drainage, removing excessive thatch and mowing until turf turns dormant are cultural practices that make turf less susceptible to pathogens, Giese says.

Snow mold comes in multiple forms. Pink snow mold and microdochium patch are closely related and they are caused by the same fungal organisms, Giese says. Deciphering between the two can be tricky. “It’s not a definitive line where one would be microdochium patch and one would be pink snow mold, but generally you will have some level of snow cover with pink snow mold,” Giese says. Two species, typhula incarnata and ishikariensis, cause gray snow mold. The brownish, orange sclerotia produced by incarnata are only noticeable after snow melts in the spring. Ishikariensis requires a deeper snow cover, although Giese says it’s possible to see the species intermingled on a tee or fairway. In most cases, gray snow mold requires 60 days of cover to infect turf.

Superintendent Jay Pritzl used Contend on the tees at Timber Ridge Golf Club last year. The picture shows snow mold activity next to a treated tee.
photo: jay pritzl

Sonnenalp Golf Club in Vail, Colo., battles pink and gray snow mold, according to longtime superintendent Neil Tretter. Sonnenalp, which sits at 7,200 feet of elevation, opens around April 15 each season, but low air and soil temperatures limit spring recovery time, thus making a late-October snow mold application the most important spray of the year. “It’s crucial that we come out of the winter as healthy as possible because the recovery time is very, very slow in the month of April and in the month of May and into June,” Tretter says.

Sonnenalp has close to three acres of greens, 2½ acres of tees and 30 acres of fairways, and Tretter slowly hardens off turf each fall, aiming to complete snow mold applications by late October or the first week of November. He annually sprays Instrata with a Medallion kicker on the three surfaces. Labeled for pink and gray snow mold control, Instrata includes chlorothalonil, fludioxonil and propiconazole as active ingredients.

“I call it the ‘the big reveal’ as the snow recedes in the springtime in March to see exactly what kind of turf conditions we are going to work with for the current year,” Tretter says. “And we haven’t had a disappointment for a number of years.”

Superintendent Jay Pritzl “deals with every type of snow mold that you can imagine” at Timber Ridge Golf Club, a daily-fee facility in northern Wisconsin. Snow mold preparations begin in September with a fall cleanup application using multiple products, including Secure and Daconil. He then sprays Instrata in late October or early November on Timber Ridge’s 3 ½ acres of greens, three acres of tees and 32 acres of fairways.

The golf season typically lasts from mid-April to Oct. 31, with close to 20,000 golfers playing the course during the 6 ½-month stretch. A small crew – Pritzl currently doesn’t have an assistant superintendent – and the competitive Wisconsin public golf landscape make a reliable snow mold program a crucial part of the job. Trying to recover in the spring can hurt business, and tax Pritzl and his crew.

Like any good superintendent, Pritzl has an inquisitive side and he closely observes the snow mold studies University of Wisconsin researchers are conducting at Timber Ridge. Contend was one of the products recently tested on the plots. Pritzl used the fungicide on tees last year, and he reported 100 percent control. “I was highly impressed on my tees,” he says. Pritzl is mulling using Contend on tees and fairways this year. Instrata will remain a staple of his greens program.

Once he completes his snow mold applications, Pritzl can expect around 150 days of what he calls “straight, solid snow cover” each winter. A northern Wisconsin winter isn’t as bleak when you know the turf will look healthy in the spring.

“It’s a great sign when we come out of winter clean,” Pritzl says. “But, honestly, I have been doing it long enough and using the same product, I’m not fearful because I have so much confidence in the product that I do use. I have more sleepless nights if we get rain or ice buildup in the winter then I do over snow mold. Snow mold I think I have a pretty good hold on and we have a good chemical program for it.”

Guy Cipriano is GCI’s associate editor.