Repairing damaged golf tees before meadow grass invades
The good news is that the warmer weather and new grass growth which will help to repair damaged swards are already starting to make their presence felt. Whilst this new growth will be a welcome sight, the double-edged sword is that this new growth is likely to come from annual meadow grass or perennial meadow grass (rough stalked meadow grass). During the early weeks of spring these species will rapidly fill the divots and scars caused during the colder months and will quickly improve the appearance of damaged tees. Unfortunately, this improvement in sward quality will only prevail for a few months before the cycle starts again.
To combat this short-term effect and to ensure tees are populated with beneficial species on a long-term basis, greenkeepers should consider the benefits of overseeding during the colder off-season: extensive trials have shown that cold or early season seeding (applying fresh seed before the soil warms to a temperature that will allow germination) is a viable alternative to the traditional late-summer over-seeding window, especially when using a modern ryegrass cultivar. Overseeding as early as March (e.g. before weed species take off) will give the sward a healthier percentage of desirable grasses, which, fast-forward seven months, will be much better equipped than rival meadow grass species to survive the approaching winter.
There are plenty of options for seeding at this time of the year; from pure ryegrass mixes (A5 Ultrafine Cricket, Tennis & Tees or A30 Rapid Sports Renovator Plus) to rye and fescue mixtures (A27 Golf All Fescue or A29 With Ryegrass Divot Mix). Specialist seed mixtures containing smooth-stalked meadow grass (A10 Golf Tees and Divot Repairs) and shade tolerant mixtures containing Poa supina (A6 Supreme Shade) are also an option.
Instead of selecting a traditional mixture because “that’s what we’ve always used”, the key factors to consider when selecting a suitable seed mixture should be the size of the tees being over-seeded, shade, air flow and abundance of traffic likely to be encountered during the sowing in and establishment period.
In reality, a fescue/ryegrass mix on a small par-3 tee will only result in the ryegrasses establishing so the fescue element will be wasted. Also there is no harm in having different mixtures for different tees.
Prior to over-seeding it is important to remove any dead material with a light scarification. Relieving soil compaction with a mini tine or a micro core filled with your preferred material will also be beneficial, and there is no harm in drop spreading or broadcast spreading seed if a drill is unavailable: a well prepared seed bed will allow seed to establish regardless if its in grooves or dimples.
Recent thinking throughout some parts of the industry also suggests that fresh seed will establish better without any additional nutrition and that the first application of nitrogen should only be applied when the plant is ready for its first mow – usually after 3-4 weeks post-emergence. A mid-range nitrogen feed (preferably in the form of ammonium nitrate to ensure good early season uptake) such as Easygreen Mini (12-12-17 & 3% MgO) should be used at this point.