To Overseed Or Not To Overseed

In recent years, the question whether or not to overseed the golf course (excluding tees and greens) is discussed with more regularity and with serious consideration. Two very important reasons for not overseeding are at the heart of the discussion. The first is to reestablish the bermuda grass that has been declining with each transition and the second reason is to possibly save money.

There is no doubt that the bermuda grass is much better off without having to compete with the winter grass, but is there any benefit to the bottom line?

Will the money saved by reducing the purchase of seed, water, fertilizer, fuel and labor overcome the lost revenue due to fewer golfers and lower fees?

For some golf course operations there may be another option; “intermediate ryegrass” or hybrid rye. It is a variety of ryegrass that crosses annual (Italian) ryegrass with perennial ryegrass. The benefit of intermediate rye is it usually costs less and it will die off as soon as temperatures start getting above ninety degrees.

The main reason we don’t see many golf courses use intermediate ryegrass is due to the fact it resembles annual ryegrass varieties more so than perennial varieties. Intermediate ryegrass is similar in color, which is a much lighter shade of green than perennial ryegrass (it will darken up with iron applications just as perennial varieties, but it may require more frequent applications depending on your tolerance for lime colored grass).

The turf density of the hybrid grass is moderate at best and the leaf blade is very large in comparison to perennial and has a more pronounced stem. The result is an inferior playing surface with very little aesthetic appeal but still a viable, green turf.
However, if you need a winter grass that will transition quickly without having to force it through water reduction or herbicide applications, this is definitely a viable option. As soon as temperatures get above ninety degrees for several consecutive days, the intermediate ryegrass will quickly turn yellow and will completely die off. The die-off period is usually two to three weeks and it is not dependent on humidity like perennial ryegrass, which can cool itself down in low humidity conditions.

Three seasons ago we overseeded the fairways on one of our courses with intermediate ryegrass. We went with a hybrid ryegrass because we had just seeded and grew in the fairways with common Bermuda grass. We didn’t want risk losing revenue that winter season, but we didn’t want to lose any ground on the young bermuda either.

Although the playing surface of the intermediate seeded fairways was not nearly as lush as perennial laden fairways, it was green and had plenty of turf to hit off of. We were able to stay competitive during the season and the fairways transitioned extremely well.

The following season we seeded with intermediate ryegrass again and had less than enviable results. Reasons for the poor stand of winter grass that year was because of temperature extremes; a very hot grown-in period followed by a record breaking cold spell in the winter. The inability for intermediate ryegrass to handle either very hot or very cold conditions is a documented characteristic that also hinders its appeal.

But again, the transition went well that following spring/summer as one might expect. Furthermore, the intermediate variety we used was fifteen cents a pound cheaper than the perennial rye we used at our other courses.

As the transition from winter ryegrass back to summer Bermuda grass becomes increasingly more difficult, and as prices for perennial seed increases, the use of a hybrid ryegrass may just be a viable option. Seed companies continue to develop new varieties of intermediate rye and improvements are being made in turf color and density. Some of the new varieties might be good enough to consider using. Think of it as just another tool that can be implemented periodically in order to gain ground on the Bermuda grass. It would be very similar to the agricultural practice of rotating crops.

In recent years, the question whether or not to overseed the golf course (excluding tees and greens) is discussed with more regularity and with serious consideration. Two very important reasons for not overseeding are at the heart of the discussion

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