Hold Water

Some superintendents are irrigating less during overseeding — and getting good results.

With irrigation water becoming increasingly expensive, superintendents are seeking ways to limit their water use, even during overseeding. Dale Miller has managed Sunbelt courses from California to North Carolina for the past 25 years, often working for management companies such as American Golf, ClubCorp and Evergreen Alliance while supervising as many as 60 courses at a time as a regional manager. He is currently director of agronomy of the four courses at PGA Village in Port St. Lucie, Fla., and has developed programs he estimates can save as much as 50 percent of the water traditionally used when overseeding greens and fairways.

One method that has worked well throughout the South begins in the summer with occasional light verticutting right through the warmest months to keep the ground open and receptive in anticipation of actual overseeding in early fall. A couple of weeks prior to overseeding, Miller suggests backing off to as little as 25 percent of normal watering in preparation for actual overseeding. He continues his application of plant growth regulators to the bermudagrass up to that time and performs a final light verticutting.

"Bermudagrass needs much less water in late summer and early fall as the physiology is shutting down the grass due to less light, lower sun angle and decreased intensity," Miller says. "The evapotranspiration (ET) rate that time of year is also much less than at other times."

When overseeding, Miller advises applying seed at rates roughly 10 percent higher than the recommended rates to account for slow germination and increased traffic, since play and routine maintenance can continue throughout all but the one or two days seed is actually being spread. Golf cars are allowed on the course and regular mowing frequencies continue. The additional golfer and maintenance traffic helps push seed down into the soil, where it has the best chance to survive. The less downtime also means more revenue.

Miller, who took the position at PGA Village this summer, says the facility has traditionally closed its courses for 10 to 12 days for overseeding during some of the best possible weather. With his overseeding method, he anticipates closing the courses for no more than two days.

Once the seed is spread, Miller continues the lower watering levels for a week to 10 days. Less water means less seed floating in the thatch layer (where it has little chance to establish itself as a healthy plant) and more seed finding its way into the soil (where it can set down roots and begin drawing needed nutrients from the ground). Player traffic and mowing helps work the seed into the ground.

Once the first seeds begin germinating, the rest will soon follow, Miller says. "At that point you go back to slightly increased irrigation rates for that time of year to fully germinate the seed," he adds. "It takes just three to five days to fully germinate. You may have to hit potential hot spots with a little extra water. But overall you will be in good shape. Greens under this program should get hand-watering in addition to normal watering on mounds and collars, where germination is notoriously difficult to [begin]."

Since the seed has already absorbed some moisture prior to beginning the higher watering rates, Miller irrigates only at night throughout the overseeding process. This saves additional water compared to courses that use larger amounts and must irrigate during the day to put down sufficient liquid. Cutting heights are raised slightly and golf cars are restricted to cart paths for a couple of weeks while the new grass plants are still establishing themselves.

This overseeding program has worked very well for Miller at the various courses he has overseen. Any extra money spent on seed is more than made up by water savings, he says.

Most Southern courses could easily delay overseeding until Oct. 1 when the sun angle is lower, temperatures cooler and water requirements lower, Miller says. But they often overseed earlier to ensure perfect conditions when rounds begin to increase in October. Some facilities, especially in the Las Vegas area, begin overseeding as early as August to be in tournament condition for scheduled professional events, Miller notes.

"In the desert, they [use] so much water partly because they overseed earlier than they should," Miller says. Unfortunately, the hotter temperatures can also kill seedlings. That forces superintendents to occasionally buy more seed and repeat the overseeding process.

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