You are probably aware by now that we took our inter-seeding efforts to additional weak putting surfaces on #3, #6, #12, #13 & #15 greens. It is our goal to increase the bentgrass populations on those greens. To do nothing would serve only to build the annual bluegrass populations. I only have to point to the complete loss of the Poa on the fourteenth green this year as proof this isn't something you would care to do.
We developed our technique through trial and error using what we knew worked best from our past regrassing efforts required to over come winter kill on greens. We also borrowed techniques of other superintendents that have successfully gassed and regrassed their greens, most notably Jerry Kershasky's work at Westmoor CC and presently at University Ridge Golf Course.
We modified our technique when we found our greens were too poorly rooted to withstand the aggressive pounding of the solid tines being used. We eliminated that step as I didn't want to remove additional greens from play. (With that said, we will address the organic matter layer that impedes drainage later in the year when the greens are deep tined.) I know you may differ in your opinion but this doesn't look like a bad putting surface after all our renovation efforts.
Pictured above is a deep verticut groove coupled with shallow aerification using close spaced .25" open spooned tines. Both a groove and a pore for seed to fall into. The cores pulled serve as a light topdressing needed to fill both the grooves and pores covering the seed. We calculated the amount of seed needed for each green and applied one half the amount of the total seed needed after each individual operation. The surrounding turf will assist in protecting new seedlings from mower injury. I will go on record and tell you the hardest job I have is keeping new seedlings alive on a putting surfaces open for play. This is due to the obvious mower mortality of immature plants unable to withstand cutting at putting green heights. For that reason alone we will be increasing the mower height of cut on those greens to improve our chances of success.
This is the best time of the year for greens renovation. I will have further updates for you in the weeks ahead. Stay tuned. _Mk