Winter Overseeding Establishment Time November 2, 2011 By John H. Foy

(L)Some disruptions and inconveniences are unavoidable during the initial phase of establishing a winter overseeding cover.  (R) Maintaining good soil moisture is a key to achieving good seed germination and ultimately a dense and uniform overseeding.  Just as the case at courses in the UnitedStates, frequent day time irrigation cycles are conducted at the golf courses in Antalya, Turkey where overseeding is an annual program for ensuring that a lush green turf cover is provided through the winter play season.    

Beginning in October and continuing into November, winter overseeding establishment is a process that must be undertaken at a number of golf courses in Florida.  However, this is a practice that has been declining with putting greens due to the improved cool-temperature color retention and growth of the ultradwarf cultivars (Champion, Mini-Verde and TifEagle) compared to Tifdwarf bermudagrass.  Large-acreage fairway and rough overseeding programs have also been discontinued at many courses in the past three or four years because of the necessity to reduce operating costs and the understanding that this is not an agronomic or environmentally sustainable long term management strategy. 

At courses throughout the central and northern part of the state, however, overseeding of Tifdwarf putting greens is still a standard practice to ensure that acceptable play can be provided during the time when the base bermudagrass is in a semi- to fully-dormant stage and play is at its peak.  This would also be true with bermudagrass tees and fairways in the upper two-thirds of Florida, and especially at resort facilities.  The mid to late fall in Florida is a great time for playing golf, but at the courses where winter overseeding programs must be conducted, disruptions and inconveniences are unavoidable.

For optimum seed germination and establishment, verticutting of putting greens and scalping of fairways are the most common practices conducted to thin the bermudagrass turf canopy and achieve good seed-to-soil contact.  This is followed by seed application, and during this process every superintendent is holding his breath and hoping that high winds or thunderstorms do not occur in non-target locations.  Once the seed has been applied and followed by an irrigation cycle to soak and swell the seed coat, frequent irrigation cycles during the day need to be conducted to maintain a moist but not saturated condition.

Especially during the first two to four weeks, the overseeding cannot be allowed to dry out without suffering a significant reduction in stand density; thus, all golfers must put up with wet and soft course conditions.  While not a luxury enjoyed at many courses, keeping cart traffic off of overseeded fairways for two to three weeks is always encouraged to help minimize damage to the emerging seedlings and limit tracking of material into perimeter locations.  Under ideal conditions, six to eight weeks typically is required for full establishment of the winter overseeding cover and redevelopment of good-quality course conditioning. 

Based on the positive results experienced at a number of courses this past winter, liquid overseeding, which consists of making regular spray applications of soluble nutrients plus a green pigment material, is a viable alternative to traditional overseeding.  Senior agronomist, Todd Lowe, discussed liquid overseeding in his January 11, 2011 regional web update:  

Winter overseeding of bermudagrass golf courses is not a unique practice to Florida and other regions of the United States where golfers come to escape the cold temperatures of northern winters.  I recently had the opportunity to travel to Turkey to assist in course preparations for the 2012 World Amateur Team Championships.  The competition for the Espirito Santo Trophy (Women’s Championship) will be conducted on The Old and New Courses at the Gloria Golf Club.  The competition for the Eisenhower Trophy (Men’s Championship) will be conducted at the Antalya and Cornelia Golf Clubs.  These clubs are in the Belek, Antalya region of Southern Turkey along the coast of the Mediterranean Sea.  This is a fairly new resort area that caters to people from Eastern Europe and the UK.  Similar to Florida and the southwest, very hot summertime temperatures dictate that all of the golf courses have a bermudagrass turf cover.  However, the majority of play occurs between September and May, and during the middle of the winter, freezing temperatures are experienced such that the bermudagrass goes totally dormant and off-color. 

It was interesting to learn from the course managers in Turkey that golfer demands and expectations for lush green turf is not exclusive to America, and as a result, wall-to-wall overseeding programs are conducted on all of the golf courses in the area.  Poa trivialis is used for overseeding of the putting greens, while ryegrass blends are used for overseeding of the tees, fairways and roughs. 

Having to import all of their seed is very expensive, and there are agronomic consequences associated with overseeding.  Yet, with this being an extremely popular winter golf vacation destination, the cost and tradeoffs of overseeding are considered to be justified. 

If you have questions or concerns about overseeding, give us a call at 772-546-2620.