[BobMoe]

We have some people who's very jobs may be on the line unless I can find some justification for continuing to build 18 greens with all USGA specs except the gravel layer. I am especially trying to find a copy of "Do Away with the Gravel Layer" by Hurdzan. Any help will be sincerely appreciated. Thanks in Advance.

[Don_Mahaffey]

Bob,
Here is a link to the specs for California method greens construction. You'll notice that the specs for Ca greens (no gravel layer) are tighter then those for USGA greens. My advice is to find yourself a good consultant to help with your sand selection and construction method. Here's the link;

http://www.sandfinder.com/california_greens.htm

[RJ_Daley]

Just out of curiosity Bob, what region or locale would that course be in?  I once heard Dr. Hurdzan storngly present a case for California sand greens at a GCSAA seminar.  I thought from what I could glean as a novice and hobbiest attendee to the conference, that it would have some dependency on the type of native soils, terrain slopes, water table depth, and overall green pad-surrounds design...

[Brad Klein]

Interesting how hotly debated "USGA-specification" greens are in the industry. One little-known fact of construction is that the only two US Opens ever held on a full set of full of such greens were 1997 at Congressional and 1999 at Pinehurst. The bulk of US venues - Pebble Beach, Shinnecock, Winged Foot, Baltusrol, are not only soil-based, push-up greens but Poa annua as well.

[John_D._Bernhardt]

I would be very interested too in the area of the country you are looking at.

[BobMoe]

For the edification of all, the golf course is located in Florida. Many Thanks for the replies --Bob

[Jimbo]

For Bermudagrass in Florida:  USGA not necessary

Do not have the energy to write the 5000 word explanation.

[Jimbo]

Sorry, on further thought my answer was probably irresponsible. Its a pretty complex question and the answer could depend on your local soils, budget, expectations, etc.

 :-/Email me and I will reply with my phone number and you can call me if you wish.

[Jeremy Glenn. (Guest)]

While I don't "know this stuff cold", as shivas said, there is still the topic of the perched water table that may be of interest.

When the subsoil is sandy (with particle sizes similar to that of the rootzone mix) the use of the gravel layer results in what is known as the Perched Water Table.

When rain or irrigation water penetrates into the green, two forces act upon it:  gravity and capilary attraction, the latter which causes water to cling to the soil's particles.  In sand, as the particles are quite small, they offer much more surface in a much denser area than the larger, more porous gravel.  Therefore, essentially, the capilary attraction of water to sand is greater than the force of gravity pushing the water down.  So water "fills up" the sandy rootzone mix layer first, and only leaches down into the gravel layer when there is no place else to go.

(Yes, it does seem counter-instinctive...)

The net result is a green that holds moisture properly, but never becomes water-logged.

If the subsoil was sandy and no gravel was used, there would be no perched water table, as the water would simply continue seeping down through the soil, rather than remaining closer to the root system.  On the other hand, on clay soil, the green cavity retains the water sufficiently well so as not to require the gravel layer.

[Don_Mahaffey]

Jeremy,
There is some recent research that shoots some holes in the perched water table theory. I think the researcher was Ed McCoy from Ohio St., but I'm not certain. The USGA method is still an excellent drainage system, it just isn't the water reservoir that it's made out to be. The California system drains similar to the USGA, but faster and not as evenly. I used to have a link to the research, I'll try and find it.  

To those not familiar with the two methods, The USGA system has sand over a gravel layer which in theory should create a perched water table because of the layer caused by the two materials of different sizes, the sand and the gravel. The Ca. system has sand only over native soil which creates what is know as a temporary water table. As it turns out, the two water tables aren’t as different as previously thought. Both greens construction methods have internal drainage tile which carries water away from the green cavity. Don't know if that makes sense, it would be nice to hear from Mr. Wilbur on this subject as he works with this stuff all the time and he could tell which conditions require which method.

[RJ_Daley]

I think that Jimbo points out that the subject is too complex to write a simple post and cover the bases.  Bob says there are peoples jobs on the line UNLESS he justifies the continued building of USGA spec greens without the gravel layer.  That seems to not be possible.  You either have the USGA specs or you don't.  You need the gravel and you need the coarse choker layer and finally the rootzone mix.  I wonder if you don't do yourselves a favor and first not kid anyone by saying that you are building USGA spec 'just without the gravel layer".  

Jeremy points out the perched water table concept VS sand green rapid drainage.  But, he looses me if he is saying that it is good to have clay soils to retain the water in a native soil push-up rather than perch it.  I fear that leads to tight soil conditions, compaction and a bad environment for rootzone disease.  I don't think you want the water to linger in the clayey soil, just perch for a time and then flush upon reaching a field capacity to interact with the choker and gravel sub layers.  

I think the native soil subgrade with sand organic amendment overlay is desirable with the drains to move the water away from the green and surrounds so as not to linger and create disease and compaction.  I can't see where typical sandy subsoils in FL would necessitate the use of USGA specs.  

Finally, I'd like to hear the archies talk about whether the USGA method unduly restricts them in designing more interesting green contours, and if the design-construction of surrounds with interesting chipping or putting humps and hollows is more easy to accomplish with California-sand or native pushups than USGA method greens?

[Ron_Mahaffey]

Either method of construction can work providing that the sand specs for both are followed.  The biggest problem with the California method is that the sand has a much narrower set of specificastions.  Either method can fail if the sand dose not meet the specification.  I have seen many so called USGA greens not work properly because of inadequate testing.  Especially, testing the compatibility between the gravel and the sand.  As all sands are not compatible so are gravels.  Failures in the California style green usually are from the use of the wrong sand or drainage that is too far apart.  The use of each also depends on the maintenance practices of the superintendent.  The California style calls for a straight sand green and tends to not work as well when organic matter levels get to or above 1%.  The UGSA specs tend to favor some soil 2 to 3 % by volume and some organic matter.  This makes the rootzone mix act more like a soil.  While a straight sand green is comparable to growing grass hydroponically.  Hope this did not further complicate a already complicated subject.  The best way to pick a construction method is to know the type of turf to be used, water quality, sand sources and the quality of sands and gravels, subsoil type and water table.  Add superintendents maintenance preference ie; spoon feeder, organic matter user, etc.

[Peter Galea]

I don't understand, you have already built some greens and are now having second thoughts? Not to be a wiseass but, remember the 7 P's: Prior Perfect Planning Prevents Piss Poor Performance. Were the architect's specs that loose?
Phone Dr. Hurdzan, I'm sure he'll explain it to you. You can get the number from his website www.hurdzanfry.com.

[Jimbo]

Okay, Bob,more energy this morning.  Re-read your post.

You've already eliminated the gravel layer for good or bad.  Lets forget it about the gravel and talk sand.

The question then becomes, what sand do you use?

There two widely followed publications: The USGA, and The Method from Cal, linked to above.  If you or your superintendent is a stud and understands soil you could say screw the publications and come up with your own spec.  This is out of the ability of probably 95% of the Superintendents, so don't blame him if is unable to do this.

You could hire a consultant to do this, but I don't know of any that has the balls to recommend outside of the widely accepted methods.  

I do think its reasonable to follow one or the other specs.  They're based on real science and have been used with success.

But I get the impression from you that those paying the bills are reluctant to pay to get a suitable sand that meets the USGA spec.  We are in May now and you probably want to start planting soon.  This is a tough spot.  If you have a source of USGA sand I'd say stick with it.  You've already saved a few hundred $k by eliminating the gravel (very expensive in Florida).  There has to be a suitable sand within 3 hours of you.  This might be double the cost of the sand available in your town, but if that sand has not been tested and you don't have the time to do it, forget it and get the USGA sand you know about.

Continue with the sand that meets USGA spec. if money allows.

If this is going to cause a bankruptcy or something, use a local sand.  You might get away with it, but should not set your expectations too high.  Bermudagrass is a tough grass and can handle alot of the additional stresses that a poorly built green might give it.

Hope this helps

[Dave Wilber]

This whole topic makes me chuckle and remember several lengthy posts I made on GCA a long time ago about the merits of USGA and other Sand Based systems and how the fall out from that particular set of posts was coming down around my ears for some time. Great fun!!

But all the experts here (including The Brothers Mahaffey) have pretty much answered the questions. I'm not sure I agree on the True California Spec being much narrower than USGA, but in fact the Cal Spec pretty much gives us a sand that does as advertised. Many many USGA spec sands that meet the specification don't always perform as needed.


>>>You could hire a consultant to do this, but I don't know of any that has the balls to recommend outside of the widely accepted methods.<<<


I know one.
 But it isn't about Stones (as it were) but knowing one's science and balancing that with available supply and with intended design characteristics. One thing I have talked about at length is that any "modular" type construction system definitely takes away from the ability to have interesting greens.

[Jimbo]

Glad to hear there is at least one consultant who will sack-up.  Thanks Dave.

I went through this process 4 years ago.  Getting an opinion on anything outside USGA spec from nationally known labs and consultants was impossible for me at the time.

Science had little to do with it.  It was fear of being sued if the greens failed, no matter what the cause: Mismanagement, neglect, poor installation, bad grass, etc.

With all due respect, Dave, I don't understand why interesting (I assume you mean lots of movement ?) greens couldn't be  built to USGA spec (ignoring of course whether the perched water table works in such a situation).  

It can be done with serious planning, and minimizing field changes.  I do realize that getting the contractor to do it properly would be a struggle.  And the architect would need to be on top of it every single day, and understand that when he changes the tie in to that green, that its going to cost.

[Jeff_Brauer]

I agree with Jimbo about using a sand that meets USGA specs in a California green, especially in a place like Florida.

I am building some hybrid greens like that now, without many worries.  My take on the narrower sand specs of the California method is that they were done in 1968 (?) and were essentially the same as USGA specs at THAT time.  The USGA has funded more research and broadened out the spec, for practical reasons, while the state of California has not!  If they had, do you suspect that the sands may have been similar?

The USGA broadened the range to accomodate more sands that will work.  My problem is not typically that owners won't pay for mix sand, but that we are presented an option of a $15 sand that is 1% out of spec, and a $50 sand that meets it.  In most climates, being slightly out of spec in some way doesn't affect greens performance to the point they will die!  But everyone is afraid to put their names on a document saying its okay to be out of spec.  (I suppose the Canadians say "OUUUT of spec"))

So, I look for performance characteristics I want, and go with them.  And I believe that growing Bermuda Grass in Florida would usually give you a pretty wide range and lattitude in your specs, with appropriate adjustments to maintenance practices, compared to growing bent in the south, or growing greens in the transition zone, or other tough zones.  (Not saying that each zone doesn't have it's unique challenges, BTW.)

For all the industry debate, I recall the original intent of the USGA spec was to find a way to use a local sand to make greens construction easier, not the monster it has become!  When I have to worry not only about particle size, but how many RPM's it takes to blend the mix, etc.  I get dizzy!

Probably too late to help, but I hope it does!

[Todd_Eckenrode]

All the bases have pretty much been covered on difference in the specs...

I would disagree with statements that it isn't possible to build interesting greens by creating green cavities (no matter the "filler" material).  It is definitely harder, for logical reasons.  What can make it work, however, are a quality shaper, an architect who's there, and a contractor agreeable to spending the time to blend the perimeter area.

[Dave Wilber]

Agreed that you "can" build interesting an in fact amazing greens if you know what you are doing with just about any construction method.

My point of view is that the modular systems (USGA, California et al..) are more difficult to move about, change, tie-in and work with over time without damaging the integrity of the way that the system needs to perform, in particular uniform sand depth which is absolute key.

More times than not, I'm finding problems or saving problems from happening because once everyone sees that something needs to be adjusted or moved about a bit it can't be done or shouldn't be done on top. In other words you can't change the top without changing the bottom. It's modular and it isn't always good for design. I keep saying that the most interesting greens I have ever seen (The Old Course) aren't Modular and are part of the landform. Since I'm a Turf and Soil guy and not a design guy, my job is to help the design guys get to where they want to go and still be able to grow grass.

At Pacific Dunes, Tom Doak and Jim Urbina tasked me to determine if we needed to seek certain sands to build with which were on site (as they did when building Bandon Dunes) or if we could shape in the sands in situ. We created a few rules and regs as far as how material would be handled and what we would do if we found material changing too much and played very careful with materials during construction. I'm happy with the result.

At Texas Tech, we don't have the liberty of any kind of good materials on site and so, we found a material that works for building greens with no gravel blanket (sorry Jim Moore, but the local sands are worse USGA sands than they are Cal Spec sands) and then worked out a way to sand cap the entire green surrounds so that Team Doak could work their magic and so that we wouldn't have firm dry and fast on sand greens and then two steps off subject the ball to the whims of the native clay soil. I'm happy with the plan and it has taken a bunch of work on our part to educate everyone as to why we are doing what we are doing.

At Rustic Canyon, upon first inspection we had a bunch of really nice material which seemed sandy enough to buld with. But careful testing and modeling and some good old digging yeilded the info that we had nice material but not nice enough to hang my hat on for building greens with. We ended up building a Cal Spec system there and it allowed Gil and Company to do what they wanted to do. I certainly would have liked to do more of the Pacifc Dunes sort of thing there, but the individual situation wouldn't allow it.

Jeff Brauer...with all due respect...we are having trouble out there with people thinking that California Spec greens are simply USGA greens without any organic matter in the sand. And from my perspective we can't build a true cal spec green with USGA sand or vice versa. Of course you know that the Cal Spec green has no gravel blanket (at least I think you do ) but many many many very "smart" people out there don't seem to understand that the entire physical system is entirely different, not just the sand spec itself. Bottom line, we have to have air, water and light to grow grass. Getting it wrong with either system pretty much takes away the Air.

Bad thing.

And I don't care what you spec or think up, if you aren't there doing the due diligence and the quality control and managing the details of the way greens are built...any situation will go out of control and give potential terminal problems. That's why I LOVE being in the field!!!

[Patrick_Mucci]

Dave,

If you were going to build the best set of greens in:
Northern New Jersey,
South Florida,
Texas
California

How would you build them?  

What would their differences be ??

[Dave Wilber]

Dave,

If you were going to build the best set of greens in:
Northern New Jersey,
South Florida,
Texas
California

How would you build them?  

What would their differences be ??

Each situation would be entirely site specific as well as adapted to individual microclimate and soil situations. You can run into just about anything, anywhere, which is why I don't do Desktop Agronomy. Can't cookbook these things and those that do have been hurting us all for quite some time.

Inside of the design planning is also the execution which is dramatically lacking in construction in many places these days.

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