Choosing The Right Sand – Some Plain Talk
Choosing the right sand(growing medium) for any golf course restoration project is critical to the long term success of that restoration… Well Duh Mark, we all learned that in turf school right? Umm, well sure we did, and did we immediately graduate in to our turf managers job right out of school. I can honestly say that what I learned in soils/turf classes does not remotely resemble what I practice in the field or preach on here. For instance, in turf school I was taught to backfill every single drainage pipe with a peastone or suitable large diameter aggregate? Those of you who read this rag regularly know that is not part of our mantra here at XGD.
After a few years as an assistant superintendent, I then began my tenure at TDIGolf/XGD Systems over 20 years ago and was quickly enlightened in the field to the benefits of native dirt backfill on systematic fairway drainage installations in SW Ontario, this basic premise is based on the farm drainage industry’s long term success. When we began our greens drainage efforts we understood we couldn’t use native backfill on existing greens as we could not compact native dirt backfill without destroying soil structure, so we used an 80: 20 sand/peat mixture percing around 15″/hour(same material as USGA greens rootzone mix). As you can imagine, it was tough for those XGD trench lines to hold enough moisture in the summer months to avoid hand watering on hot summer afternoons. So, we quickly began using a more organic greensmix backfill more similar to a tee mix or divot mix, with a perc rate between 1″-5″/hour. My take home point here is we use this type of mix for compaction perfection only, not for surface water movement. This type of backfill on greens allows us to return the putting surface to tournament play 1 hour after the crew leaves the green.
As an example, this picture below illustrates what appears to be some fairly decent material coming out of a soil greens XGD trench, however what you cannot see until close inspection is the fact that the 4″ of sand topdressing has mixed with the subsoil clay soil profile below to give the appearance of an excellent backfill material.
The following picture shows a typical XGD greensmix backfill mixture of the 60:20:20 variety, percing between 1″-5″/hour:
At XGD we really don’t caught up in the general characteristics of any specific mixes. We have and will continue to use the following mix compositions: 60:20:20, 60:30:10, 60:40, 70:20:10, and 50:20:20:10 in true pushup soil greens. These mixes consist of sand,soil, peat and compost. The most important factor for us is the percolation rate(or Ksat rate or infiltration rate) in inches/hour. For pushup poa/bent greens we use 1″-5″/hour. Generally, for a failed sand green installation we will use a product in the 5″-10″/hour category, but this will vary once soil test’s are observed.
For pushup bermudagrass greens we will generally use a 90:10 percing at 15″/hour, as the bermuda will thrive in the sandy trenches and due to the fact that it produces so much organic matter naturally.
For fairways we generally use a coarse sand percing in the 10-20″/hour category. Obviously, the difference being height of cut for fairways. As well, keep in mind this fairway sand is for our 3.5″ wide XGD trench, and I would not recommend it for drainage pipe beyond our 2″ pipe.
In summary, after 20 years of doing this and over 10Million square feet of putting surface drained, I have learned there really is no perfect backfill for any or all situations. But, taking the time to get it right it the first time is something of a strength for us at XGD, and we lean on this strength of ours and pass it on to our clients. Hey, nobody’s perfect, but when you have been in business as long as we have, there isn’t going to be that much occur out there that we haven’t seen before.
Cheers, Poor Old Dirt & Grass Farmer