Golf Greens Overseeding

Overseeding will also typically take place at the same time as top-dressing, although not where monthly top-dressings are practiced.

Overseeding with grass species which produce optimum playing surfaces has traditionally been with Chewings fescue and Browntop bent and these continue to be the main stay of most golf greens.

The growth of grass is not a uniform activity which produces a consistently even surface, growth is variable between species and cultivars. A greenkeeper needs to undertake a range of activities to produce a surface with uniform coverage – density and evenness of grass height - for the entire year.

Grass species do have different patterns of growth and development and the traditional grasses, to which can also be included Slender Creeping Red Fescue, complement each other very well. The red fescues produce a more upright growing plant whilst browntop bent grasses have more lateral as well as upright growth which help create the very dense swards desired of golf greens.

Growth does vary over the year, with red fescues typically being have earlier spring growth than browntop bent, which becomes more dominant in growth from late spring, May, onwards. The periods of the year when growth is slow is when the most noticeable difference in grass species growth rates can be observed.

Browntop bent, as can Perennial ryegrass, where chosen to be sown into a green, can make slow growth at colder times than annual meadow grass; the latter being a common yet most undesirable and unsustainable grass on green which aim to produce good putting surfaces. The consequence of having a wider range of grass species on greens is that during the relatively very slow to slow growth periods, some species will be effectively dormant (such as annual meadow grass) but will be interspersed with species (such as browntop bent) which have irregular growth during short and intermittent warmer spells.

Many greens have a predominantly browntop bent and annual meadow grass composition, with red fescue, unfortunately, being a much smaller percentage. Some greenkeepers consider that as red fescue does not appear to survive well in their particular greens then they reduce or eliminate red fescue from overseeding mixture. However, red fescue is a relatively fast seed germinator and can readily colonise thinner areas at the expense of annual meadow grass. The browntop bent species might then take over from the red fescue but it then isn’t having to out compete annual meadow in such high quantities. So, red fescue, where it has limited longevity in some greens should still be considered as an essential species to use in overseeding, being used as an initial competitor to annual meadow grass and giving time for the slower germinating and establishing browntop species to develop and then take over from the red fescue.

Browntop bent seed is very small and will typically settle towards the bottom of a grass seed bag where it is included within a mixture with red fescue. To encourage a more uniform spread of the different seeds it is important to shake up the bag to better mix it before pouring into a distributor. Alternatively, purchase separate bags of red fescue and browntop bent and sow these separately.

Adjustments and improvements to working practices, even small ones, are needed in the continuous battle to reduce the spread of annual meadow grass and all the negative impacts this grass has on a golf green.