Efficiency in overseeding
Trinity Forest Golf Club in Dallas has experiment with different overseeding tactics on its practice range. On the right, is Primo-treated turf.
Photo courtesy of Bill Weller

Efficiency in overseeding

With water becoming increasingly scarce and expensive in some regions, superintendents are deploying creative tactics to boost establishment.

November 26, 2019

Superintendents typically keep a sharp eye on two important markets during the fall season: water and seed. How these two commodities behave separately affects the way they will efficiently conduct overseeding, in the South, and summer-stress replenishment seeding, in the North. Or not. 
Routine overseeding and damage repair are, of course, among the most water-intensive enterprises superintendents undertake (outside day-to-day irrigation). And the water market is going only one way these days. According to www.CircleofBlue.org, residential water costs (one of the few universal metrics from region to region) in Tucson, Arizona, for example, have nearly doubled since 2010. From 2017 to 2018, rates increase there between 6.1 and 8.8 percent annually depending on category. 
Turf seed remains more of a true commodity, where pricing fluctuates according to verifiable supply. Anyone who recalls the tight, expensive 2018 market, however, has already made the connection: Efficiency in the overseeding process is paramount. 
“Germination must be widely achieved while keeping strict tabs on water usage,” says Jim Spindler, director of agronomy with Ocala, Florida-based Ecologel Solutions. “Otherwise, fall seeding becomes impractical from a budget perspective — or, in the damage-repair scenario, it becomes a matter of addressing these areas but not those.”
Bill Weller, a golf course superintendent at Trinity Forest Golf Club in Dallas, believes the difficulties in achieving that balance, along with cost, have contributed to a decrease in the number of facilities that undertake overseeding.
“I think over last decade or two courses have shied away from overseeding due to summer turf quality issues, and general cost of seed and maintaining overseed,” Weller says. “Especially given that by using pigments and paints you can create a similar visual at a fraction of the cost. I think for the most part there isn’t any real revolution in overseeding. You just need to use cultural practices to ensure good seed-to-soil contact — and time it when temperatures are good for ryegrass establishment.”
Clearly, for superintendents who continue the overseeding practice (especially the desert and other areas where they really don’t have a choice), it’s a balance and an increasing number of superintendents, Weller included, are cleverly deploying products/strategies to help achieve that balance. 
“I started with Hydretain about two years ago and I really like the benefits,” says Johnny Webb, superintendent at Desert Sands Golf & Country Club in Mesa, Arizona. “It’s been a night-and-day difference in terms of not having to water as much to promote germination. I put it down twice a year, in October or November, then again in March or April when I’m coming back with the Bermuda.” 
Hydretain is what’s known as a hygroscopic humectant. It’s often lumped in with wetting agents but its functions are quite different. According to Spindler, whose company manufactures the product, Hydretain actively coats plant roots and seed husks, attracting moisture already present in the soil profile — moisture in the form of water vapor or humidity that would otherwise be lost to evaporation. 
“Benefits to the fall seeding process are pretty obvious,” Spindler says. “Hydretain helps maintain moisture on and around the seed. As such, it helps that seed more quickly imbibe/absorb that moisture. Studies and field use prove that seeds coated or otherwise planted in conjunction with Hydretain germinate faster and establish better — with better root development.”
Ecologel was founded and remains based in Florida. So, while Hydretain is available nationwide, it developed one of its core popularity there — in part because of the efficacy it lends to the overseeding process. “Typically,” Spindler says, “superintendents in warm climates will open up the soil (by verticutting, commonly), apply the product in liquid or granular form, lay the seed down, and then water.”
Without a Hydretain application, the overseeding rule of thumb has been steady irrigation for 10 minutes out of every hour throughout the process. Golfers (especially private club members) dislike that sort of frequency, naturally. But germination is paramount. And so irrigation schedules during overseeding rounds traditionally interrupt or interfere with play. They can also leave playing surfaces soggy. 
The advent of Hydretain as part of the overseeding process typically cuts that watering regimen by as much as half, according to Webb. 
“That’s really the main thing I notice with this product, and not just with overseeding but throughout the summer,” Webb says. “I’ll do an application after aerification and I find I don’t have to water as much. I can go two to three days and things stay just fine — even in extreme summer heat. In the past, I had to water every day and if I didn’t, things went south.”
At Trinity Forest, Weller, who oversee the maintenance of the club’s practice areas and short course, hasn’t stopped overseeding altogether, but he has limited it to driving range tees and large practice facility — about 5 acres in total. Still, he remains as concerned with accelerating germination as anyone: “I've heard of people topdressing afterwards, basically ensuring seed to soil contact, and I tried it this year. It was pretty successful, although the downside is the tees are a little too ‘sandy’ in my opinion, during the ryegrass' early stages.” 
More interesting, perhaps, is the method he’s undertaken to pump the brakes. 
“I think the one thing I may be doing differently these days is using Primo Maxx at early stages to try to encourage tillering,” Weller explains. “Tillering will inevitably happen, but that's where timing when overseeding is so important, because the longer it takes for the plant to mature, the longer you have subpar turf conditions. For example, if you seed too late in North Texas, it can get cold and rye might take one to two months to grow as much as it would in one to two weeks of higher temperatures.
“The PGR effect also helps lower mechanical damage by reducing the number of times we mow each week during the early growth stages… To be honest, I haven't really heard of it being used for that purpose — I assume mainly because of the cost associated. But the label has all the directions. You can visually see the difference; the treated areas seem to have matured more quickly. 
“I think the idea for me came from being tired of pouring fertilizer on rye and then dealing with ‘bailing hay’ afterwards. The quality of cut was never very good and you always had to have multiple people ready to blow clippings. I was just thinking about it one day and how growth inhibitors work and started reading the Primo label.”
It always pays to read those labels … 
“I saw its recommendations for overseeding and just start playing around with rates last winter (because we had a couple gallons left over from the previous year),” Weller says. “I found there are a couple regional USGA articles (from 2014-2015) about using Primo for establishment, but I'm just not sure how widespread this is, in practice. 
“This year was the first time I used it as an establishment aid and I definitely felt like I saw results. I think it's just all about rates and timing and finding what works and what fits the budget. But it saves me labor and the turf quality/after-cut appearance is much improved.”
Weller says his first applications are approximately 600 GDD after seeding and just over 400 GDD after germination (GDD base temp 32*). 
“I've also been playing around with Anuew, and saw some great Poa [annua] seed-head suppression last year, so I'm going to look at that more this winter,” he adds. “I think the only downside to using PGRs with overseeding is that the rye survived much longer into the summer than I expected, even after using Kerb as a transition aid. So, I think using it as an establishment aid is great, but I may need to tweak its usage in the spring.
“I think it comes down to budget and the labor available for applications. I think I probably use around 2 gallons of Primo on ryegrass a year, and that correlates to around $600 after tax for around 5 acres. If you're overseeding 20 to 30 acres of short grass, it definitely becomes more of a burden on the budget.”
The larger budget consideration for most superintendents is the water itself. Hence the need for germination to be as efficient as possible, at the lowest possible cost. Trinity Forest is a private, upscale club that opened in 2017. Older irrigation systems may not provide the coverage a superintendent needs — to reach stress-damaged areas, to provide reliable wall-to-wall coverage during overseeding. 
“It’s a difficult balance to be achieved each and every fall,” Spindler says. “We think of Hydretain as an insurance policy that eliminates the need for overwatering while ensuring there is enough moisture for the young root to thrive — oftentimes without that afternoon watering altogether.”
“Our putting surfaces here are true push-ups, no drainage to speak of,” Webb reports, from Arizona. “They’re domed, these greens. It’s hard to keep the moisture on the higher spots; it’s difficult to hold the water in there so it doesn’t run right off. And, of course, the water wants to run. With H30, it holds much better. I really struggled with these domes the first two years I was here. The last two years, they’ve been money.”
Hal Phillips is a Maine-based freelance writer, managing director of Mandarin Media and frequent Golf Course Industry contributor.