For my concern, the time of year where drainage of low spots on greens, USGA greens notwithstanding, is in the winter when standing water is frozen before it sheet drains off the surface. If that standing water freezes into ice it can shatter poa annua crown tissue.
I don't think an XGD system will move that standing water off the surface, in the winter, if the ground is frozen. Or will it?
I have been thinking about doing a directional boring, under a push-up green, to one low spot that collects water.
My thinking is I could cap the pipe at 4 inches under the surface. And just before the ground freezes I would cut in a hole cup over the top of the pipe, pull the cap, and let the water drain to the hole cup and off the green all winter.
Anyone out there have any experience with something like this?
I was thinking that if this works well on the one really bad spot, I could begin doing more of these on other spots. All of these pipes could be brought back behind the green, below the frost line, and connected to a tile line for out-flow. With directional boring, this system could be vertical at the source, and below the frost line at the outflow so it would never freeze.
The thought also occured to me that I could place center sod cups over these lines and pull them in the summer time during heavy rains. But that might be a little too ambitious.
Anyways, the old push up greens were not always built with perfect surface drainage, and the build up of bunker sand layers around the edges can block off some of the original surface drainage routes. Sometimes the organic matter buildup on the fringe can also dam water up.
For various reasons, push-up greens can become slow to sheet drain water off in certain areas, and the worst thing about that problem is the vulnerability that Poa annua now has to crown hydration and ice formation. I'm hoping I can find a solution to this, short of remodeling the surface - many of these quirky surfaces are wonderul playing surfaces with lots of quirck, interest, and character. But, agronomically, they can be difficult to manage.