You have now overseeded anywhere from one half to 100% of the entire course. Hopefully, good seed with good weather has provided you with a good emergence. Members and visitors are chomping at the bit to play golf. Here are some tips for getting the overseed up and running.
Greens usually take a real beating right after overseeding because of high traffic and the juvenile condition of the plants. Many greens are played on when they are at 5/16" or 1/4" in height (first two mowings). This is due to having to meet the demands for "opening day." Reducing mowing heights on the greens is a gradual process. Here are some tips to follow which should minimize any drastic responses to successive decreases in mowing heights on the greens.
1) Drop the height no more than 15%-20% of the cut, at any single mowing.
2) Go from 5/16" to 1/4" (8/32") by double mowing at both heights in the same day. Mow daily at 1/4" for 3-4 days.
3) Go from 8/32" to 7/32" with a double mow at 7/32" the same day. Mow daily at 7/32" for 3-5 days.
4) Mow at 7/32". Roll one direction. Mow again at 6/32". Do this all in the same day. Mow daily at 6/32" for 3-5 days.
5) Mow at 6/32". Roll one direction. Mow at 5/32". Double mow the next day at 5/32".
6) Repeat this process to lower your height to the final height (1/8" or whatever the desired height will be).
Note that double mowing at the existing height will be less stressful on the grass once you initiate the new lower height. Best results will be achieved if you mow at the old and new height in the same day. Otherwise, you may scalp the green. You can add the rolling event in between the "old" and "new" mowing height. This helps to minimize any scalping and allows the grass to "grow into" the new (lower) height as it stands up into the bed-knife. For those of you with triplex mowers, don't make four clean up passes with a double mow. Just make one. When double mowing twice on a "height reduction" run, just make one clean up pass at the high height. Finish the "lower" clean ups with a walk behind. This will save the turf at the margins of the greens from the multiple stresses of a "new" mowing height and turning with the triplex on the clean up pass.
Fertilize the greens every 5-7 days with ½ to 3/4 lb. of -N- from a complete fertilizer (N-P-K). If you cannot keep up with the mowing outlined above, then adjust the fertilizer accordingly. Otherwise, you will promote scalping if you have too much fertilizer and not enough mowing.
The program listed above is for setting the greens to final height, before the weather gets cold. With cooler temperatures, you will have to take more time to achieve final greens height, since the grass will grow slower and tiller more slowly.
If you scalp too much at any one mowing event, follow with iron and quickly available -N-. Stay at the "new" height until the grass recovers.
FAIRWAYS - APPROACHES - TEES - ROUGHS
Eager golfers are going to take a lot of divots out of the tees and fairways. So instead of giving away hats and sweaters at the clubhouse, give away seeded-sand cups for re-seeding divots. Hanging cup holders are available from cart manufacturers and the golf pro or G.M. should follow up on this.
Golf cart traffic control is a must for assisting overseed success. Rope off either left or right side exits from paths and again around aprons and green exits. Alternate the drive path directions and exit points every 2-4 days.
Weak areas on exit points can benefit from a select aerification from either 1/4" solid tines or water injection. Apply ½ lb. of -K- from 0-0-50 on these spots and water in.
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.