6/12/2012 9:06 AM
I've got some thoughts on this process. We have a similar elevation and snow cover to what you described. I used a 3 pt graden at 3" spacing a few years back and went in about 1" deep or so. We did not have the sand filling units, and it turned into a disaster. After removing the material, the grooves somewhat closed up. After topdressing, even further, and there were very visible scares for quite some time. I had to lightly topdress often and drag to span the indentations and voids to keep a true surface. I also did this later in the year (early october), and that may have led to the poor recovery and poor overwintering of our greens. I originally wanted to dry the material down and blow it away or drag it in with new sand, but while trying to accomplish this process during golf, there was going to be no chance. I had to use a debris harvester to broom it away. Another variable to consider.
lately, I've adopted a different philosophy after having some samples to done with ISTRC and talking with their representatives. In our conversation, I surmised that if you can't fill the cuts with sand before traffic/equipment, one is better off aggressively aerifying with shallower tines, and a small diameter in order to remove a sufficient amount of material, but allowing for the voids to remain open. I am in the belief it is best to remove the entire plug that is pulled, but in this instance, perhaps the best thing to do would be to spread the sand, then pull the plugs (two directions if possible), then drag in all the material in the hope that the OM you want to remove will stay out of the smaller holes, and can be blown off later.
We use a procore 648 with the ten tine holding block and I used a 3" depth side eject 3/8" hollow tine. Turns out to be about 1"-1.25" spacing with this setup. With the quad blocks on this unit, a single guy can go through alot of square footage at a pretty fast pace. With the multiple small holes, we pulled a great deal of material up, and the recovery time was about 7 days. Another step to the process was we aggressively verticut 2 directions with normal triplex verticutters prior to the aerifying process, furthering a spot for the sand to work into.
I no doubt believe the graden is a great machine, but site,equipment, and rootzone material may alter your approach and create a apples to oranges comparison. My guess would be that you could aerify twice and recover just as fast as if you would go with the graden. From my experience, the speed of the process is increased as well. But, again, what worked for me may not be the best case scenario for you.