David M. Kopec, Extension Turfgrass Specialist
Overseeding is pretty much done but there are always some areas which need touch up on the golf course. They range from total re-seeding to using simple stress alleviation techniques such as careful irrigation and golf cart traffic control.
Here are some tips for post overseed correction problems:
1. Some clocks may still be on the original germination or grow in operation cycles. This is probably providing too much water. Multiple programs may be running and the germination may be coming on at night. Check it out!
2. Some heads may be running on block systems for an extra amount of time for accommodating the driest turf areas. This can make a swamp elsewhere. Make sure the sprinkler heads have matched precipitation rates for the amount of area they are covering. This is critical in a block system (many heads running off one solenoid). If the dry areas are hard from irrigation runoff, then solid tine aerify with a small walk behind aerifier. Leave the holes open. This can occur on green exits and tee entry points, as well.
3. Have a swamp? Once again, check for mis-matched heads or adjust single head run times on a valve-in-head system. After you have corrected any irrigation problems, aerify leaving the holes open.
Quick Wear Outs:
This is often caused by identical traffic patterns from leaving the tees. Rotate traffic as much as possible. Use rope! Endorse bounty rewards for golfers who catch those offenders, as well as polo players. Polo is played from a horse on tall grass.
Keep mowing regularly, coupled with good fertilizing, when the weather is warm! You will get your best response for grass tillering (multiple shoots coming out of the base plant). Don't scalp the grass! There is nothing worse than scalping to weaken the new overseed.
After November, switch over to nitrate forms of fertilizer. Avoid straight ammonia forms. Select products with ammonium nitrate, potassium nitrate, or calcium nitrate. I believe a good shot of phosphorous (at least 400 lbs. of -P- per acre) strengthens the plant for cold weather. Include at least 200 lbs. of -K- per acre in November. In high sand soils, a complete fertilizer (N-P-K) is the easy way to go. Add the nitrate fertilizer if you need to. On real "farm" soils you can get by with -N- alone until it gets cold. Here, try and apply -P- as well.
To keep the turf "green" before cold weather, spray iron at 4 ounces per 1000 ft2 every two weeks. Spray it in the morning and let it dry all day. Try chelates on tees and greens. It's worth the price over ferrous sulphate alone, which is okay on the rest of the course.
Climbing Mt. Baldy:
Here are some tips if you get stuck with bare spots and must reseed.
1. Hand rake or lightly verticut for good seed/soil contact.
2. For large(r) areas use a calibrated spreader.
3. Topdress with composted steer manure. The manure will provide extra heat and hold moisture longer. This is critical since the irrigation is on a "play" schedule.
4. Don't let these areas dry out.
5. Always have seed/sand at the tee boxes and in the carts for fairway divot repair.
6. Include some Poa trivialis in the seed mixture (10% Poa trivialis, 90% ryegrass). The Poa trivialis will come up when it's cold.
7. Those of you who find the greens very weak can reseed lightly with Poa trivialis. Use about ½ to 1 lb. seed per 1000 ft2. You can put is in topdressing sand for application.
8. For ryegrass seed, you can pre-germinate seed. Follow this procedure exactly.
a. Find a clear space in the garage or shop.
b. Get a clean 32 gallon plastic garbage pail.
c. Get some burlap bags, or easier yet, the empty ryegrass bags from overseed.
d. For each 32 gallon pail, place ½ bag of seed (25 lbs.) in the pail of water. Do this at 8:00 am.
e. Change the water at 12:00 noon.
f. Change it again at 4:00 pm.
g. Let it sit overnight.
h. At 8:00 am the next day, spread the seed in newspaper on the garage floor. Rake it several times to allow the seed to dry out.
i. Gently crumble the seed with your hands after it dries.
j. That afternoon, reseed with a centrifugal or drop
spreader. Small areas can be done by hand. Try and get about 10 to 15 seeds
per inch. Follow with the manure topdressing. Water accordingly for germination.
This will greatly speed up the germination and emergence process.
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.