David M. Kopec, Extension Turfgrass Specialist
Has the winter weather caught you with your (bermuda) shorts down? To almost all of us, it has this year. The unbelievable warm November kept the bermudagrass growing aggressively right up until the middle of, or even into late November. Even bermudagrass that was severely scalped at overseeding time had plenty of time to grow back and compete aggressively with the ryegrass. The overseed looked pretty good with a lot of bermuda underneath it. But, when the frost hit with successive cold high time temperatures, dormant bermuda abounded!
As a result the turf shows an under story canopy of dormant bermuda. The turf in this case looks like a sponge (bermuda underneath) with single tiller ryegrass plants partially covering it.
Other conditions appear as swirls of bermudagrass (like cotton candy) which pockmarks the otherwise o.k. ryegrass. This is especially true on Tifway (419) and is less so on common bermudagrass.
The third usual case are large strips of turf which have less ryegrass and more bermuda visible at this time. These stripes are from a mechanical process like mowing, scalping, verticutting or dragging. The bad looking areas in long strips got less treatment than then the other areas.
Courses which have seeded at 650 lbs. and above show minimal bermuda syndrome. Those seeded at lower rates can be spotty or thin, and show the symptoms mentioned above.
What's the Fix?
If the ryegrass is only in the one or two tiller stages and there's a 1/4" or more between plants, note the following.
(1) Do not lower the mowing heights in the coldest times of December and January. You might think that lowering the mowing height will shave off the brown bermuda, This will only stress the ryegrass when it is in the one or two tiller stage. While new leaves will emerge from the shoot, new shoots (tillering) will be minimal due to the cold temperature.
(2) Add fertilizer which is in the nitrate form. Potassium nitrate, calcium nitrate and ammonium nitrate is the ticket here. Apply 1.4 lb. -N- every two weeks. Stay at the normal mowing height. This will fatten up the leaves which will help with percent green cover.
(3) Add Iron. Apply Ferrous sulphate at 11 lbs. per acre twice per month. Let it dry on the leaves for one day.
Large Bare Areas
If these areas have less than 20% ryegrass they can be replanted by either slit seeding or lightly verticutting. Follow this recipe.
(1) Verticut into the bermudagrass 3 to 5 directions. Lightly!
(2) Add seed. Ryegrass at 18 lbs. per acre. If adding Poa trivialis, go with 14 lbs. ryegrass / 2 lbs. Poa triv per 1000 sq. ft. (pre-germ, if you can).
(3) Cover the seed with 1/4 A of composted steer manure. This will hold moisture from a single daily irrigation to prevent drying out and hold heat from the sun which is necessary for germination in cold weather.
If the fairways, roughs, or approaches need touch up, (70% ryegrass cover existing) then the safest operation is generally slit seeding. Make multiple passes in multiple directions. This is essential when overseeding. If you add Poa triv, make sure the seeder will distribute the small seed of Poa trivialis evenly. You may have to apply both grasses (rye/Poa triv) separately due to extremes in seed size.
Covers for Tees and Greens
Turf covers can be used to cover tees and greens for cold weather protection. Cover them at night and remove one-half hour after sun rise when the greens and tees are in use.
If you are reseeding greens or tees because of lack of overseed cover (not in play), then check with the manufacturer if your cover is good to keep cover both day and night.
Paints - Dyes Colorants
Turf paints and dyes are readily available for use. Usually the final solution calls for a 10:1 dilution of water to paint or dye. This should cover about 10,000 square feet. Check with your dealer.
If you need some color for a one or two day event, then double up on some standard turf dye marker. Apply the standard 1x rate of dye at a high gallon per acre final solution. Then repeat this in another direction. The trick is (1) high gallon age, (2) low ground speeds, and (3) multiple directions.
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.