It's hard to believe where the time goes from September 1 to December 31. It's the most hectic four months any golf course superintendent can live! If overseeding wasn't too early, it was too late, each which experienced a cold snap and an 'Indian summer' to boot. Well, December is the 'eleventh hour' for sprucing up the turf for early winter, and also the coldest and slowest time for turf to grow and respond to management treatments.

If greens and tees are thin, ask yourself why? Did you overseed too late, at to low a seed rate? Did you "mow down" to reach green height too quickly, or did you have poor germination due to irrigation or standing water problems?  Poorly drained tees and greens will benefit at this time from 1/4" solid tine aerification, or water injection aerification. Follow this with 1/8 lb. -N-/M of water from a soluble nitrate -N- source three days before aerification and another 1/8 lb. -N-/M three days later.

Everyone wants to play golf before Christmas and crowd control is often a problem. Keep on rotating traffic paths, or stick to one exit direction off the tees if the overseed turf is already ruined. Aerify these areas to promote drainage and some green color, as well. Get the Club GM, the Director of golf and the Golf Pro to support traffic control programs by visiting with the greens chairman, the greens committee, and club members. A general announcement and the  appropriate use of signs on the course are mandatory.

Spot re-seeding:

There are always touch-up areas that need to be re-seeded. At this time, the soil is as cold as it's going to get. In order to achieve some results, here's what I recommend.

(1) Aerify the affected areas with 1/4" solid tines.
(2) Pre-germinate the seed in a clean 55 gallon drum or clean plastic tank.
(3) Seed in one direction, then brush into the turf cover.
(4) Topdress with composted steer manure as a dusting on greens, or up to 1/4" on fairways, tee and roughs.

*You may be forced to overseed with Poa trivialis, which germinates in cold weather better than perennial ryegrass.

*To pre-germinate seed, place 25 lbs. of seed in a burlap bag in tap water, with an air hose running continuously at the bottom of the barrel. Change the water at 6, 12, and 24 hours. At the end of 36-48 hours maximum, pour off the seed on a fine screen and allow to dry. Then sow this seed on the soil as normal. The seed should not have the white root (radical) popping out yet. If it does, do not let it dry, but spread it (by hand) over the re-seed areas.

The dead of winter brings on fertility challenges and sometimes odd color appearances on turf. Both sand tees and greens often exhibit deficiencies of phosphorous, potash, nitrogen and iron when the Christmas freeze comes. Fairways, roughs and other natural soil areas which have high silt and clay contents usually exhibit iron deficiencies first, followed by poor growth from lack of available nitrogen. These cold weather nutrient deficiencies have some tell-tale signs!

Phosphorous deficiency first appears as dark green (but stunted) growth. This is followed by the more recognizable purple colored undersides of leaves and the leaf stem (leaf sheath). This occurs on ryegrass tees and greens, and on bentgrass greens, as well. Treat these areas with phosphorous fertilizer, at the rate of 0.75 lb. of -P-/M every twenty days. I have seen a very quick response from ammonium polyphosphate (liquid fertilizer) and from either super phosphate (0-27-0) or triple super phosphate (0-45-0). Smaller grade materials work better. Water it in during the heat of the day (lucky clubs -- closed one day/week).
 Potash deficiencies start as a yellow-orange (Sedona-like colors) bronzing on the leafs. The leaf edges usually show some shredding. Apply 1/4-1/2 lb. of -K-/M every twenty days. Use 0-0-50 (potassium sulfate) or potassium nitrate (14-0-44). Note that with potassium nitrate, you get nitrate nitrogen, as well.

Nitrogen deficiencies can show up as weak and unthrifty turf, which is lighter (off color) than it should be. This should be confirmed by looking at the oldest leaves on the stem. If they are light green, yellow or straw, then nitrogen is low. In the dead of winter, turf will respond best to nitrate fertilizer, rather than just ammonium sources. Therefore, your low-cost options include ammonium nitrate, calcium nitrate, potassium nitrate. Usually 1/4 lb. -N- every ten days is sufficient.

Three way (complete N-P-K) fertilizers may be the easy ticket, but be sure you (1) look to observe the source of nitrogen (quick vs. slow release/ammonium vs. nitrate) and (2) finish off with another fertilizer to cover the specific deficiency, if necessary..

Iron deficiencies occur readily in the winter months. The turf will be off color and the youngest (emerging) leaves in the shoot will be yellow, or on ryegrass even white. Apply iron at 2-4 ounces/M. Ferrous sulphate is inexpensive, but will not last long. Chelated compounds last longer, but are more expensive. Apply iron spray compounds at 10:00 a.m. and let dry all day before irrigating as usual.

Use the 'heads up' approach on start times when frosts occur. Under desert conditions, irrigation right at or after dawn may cause ice formation when the air is very cold, still and very dry. Activity on frozen turf is usually catastrophic. Don't roll incessantly to increase greens speeds, on a regular basis. Double cutting and double rolling is good for a tournament. However, relief is necessary after this.