[PHOTO: Stacy Revere]
Slapping the sand off your shoes after leaving a bunker is a norm that’s often first learned by young golfers watching tour pros on TV. Phil Mickelson, in particular, makes it look pretty cool. But how important is it for us to do that? From an agronomic perspective, does it really matter if we keep bunker sand off the greens?
To learn more, we caught up with Chad Allen, the director of agronomy at The Club at Chatham Hills in Westfield, Indiana. Allen is a seven-year member of the Golf Course Superintendents Association of America.
Golf Digest: Chad, as you know, many golfers slap the sand off their shoes after leaving the bunkers to help keep that sand off the greens. Of course, limiting the amount of bunker sand on the greens can help the ball roll smoother when we’re putting, but let’s focus on the course maintenance side of things. From an agronomic perspective, are we doing any damage if we don’t slap this sand off before walking onto the green?
Allen: That’s a good question because obviously a lot of bunkers are around the greens, and you get that splash of sand onto the green.  I’m sure most people are familiar with top-dressing greens, when we’re covering them with sand. The problem is that top-dressing sand and bunker sand are different.  Bunker sand is more angular so that it can stick on a face.
A couple of different things can happen when you have two different materials stacking on top of each other for an extended amount of time, like what happens when bunker sand mixes with top-dressing sand. You get what’s called layering, which causes the turf to hold too much moisture because the turf with two types of sand on it can’t push water through.
Another thing that can happen is if the bunker sand on the greens is not removed prior to rolling or mowing, you could really damage the equipment because bunker sand has a larger particle size. The sand could shear the leaf blade.
When you say that bunker sand is more angular, what does that mean?
You can look at sand like ball bearings. When we build greens, we don’t use all the same types of sand – we use different grades – but they’re all rounded so that you don’t get an impermeable surface that water can’t flow through.
Bunker sand is more of a silica-based sand. Think of it as having more edges on it. It’s a little more jagged. If you take a hammer to a rock and bang it, you get those shards that come off. That’s not a perfect analogy, but it’s a good characteristic of what that sand is like.
So dragging bunker sand onto the greens is this something that you’re actually worried about on a day-to-day basis?
It’s not the end of the world, and it’s not anything that I personally would lose any sleep over. That said, you’re going to be way better off if you hit the sand off your shoes into the rough or even the fairways instead of carrying that sand onto the putting surface.
