Topdressing Putting GreensA Panel Discussion

Moderator:

Panelists:

Stanley J. ZontekDirector, Northeastern Region, USGA Green Section

John Berarducci, Golf Course Superintendent,Skokie Country Club, Glencoe, Illinois

Raymond P. Knapp, Golf Course Superintendent,Tuckaway Country Club, Franklin, Wisconsin

James T. Snow, Northeastern Agronomist, USGA Green Section

Charles B. White, Southeastern Agronomist, USGA Green Section

Douglas T. HawesDirector, Mid-Continent Region, USGA Green Section

Donald D. HoosDirector, Western Region, USGA Green Section

Moderator: Gentlemen, our paneltoday will deal with one of the mostimportant management operations thatcan be performed on putting green turf.Our panelists represent the entire coun-try. Their comments on topdressing areof national significance.

The first question therefore is, whyare putting greens topdressed?

Hoos: There are many reasons totopdress greens:

1) Fresh topdressing encourages newgrowth of grass shoots and stems toforma dense, fine-bladed turf.

2) Thatch control. Under heavy fer-tilization or high or infrequent mowing,thatch becomes a major problem. Top-dressing checks dense thatch accumu-lation by mixing soil particles with plantmaterials which, in turn, encouragesmicrobial activity that breaks downthatch and converts it into valuable soilhumus.

3) Reduced disease and insect activity.4) Alleviate compaction. T opdressed

greens usually have better holdingqualities for the golfer. The materialprops the grass plant and helps it toabsorb compacting forces. It developsresiliency when a high quality top-dressing is being used. This point is ofparticular importance on heavily-playedgreens.

5) Weed control. Most weed seedsrequire light to germinate. Regular top-

22 USGA GREEN SECTION RECORD

dressing buries the seed and thus reducesthe potential for weed invasion.

6) Protection against winter injury.In regions where this is a problem,topdressing applied late in the fall helpsto insulate the turf against winter desic-cation and helps to reduce the severityof winter turf diseases.

These benefits are in addition to theimproved putting green quality usuallyachieved because of the smoothing,firming and speeding of the puttingsurface that topdressing provides.

Moderator: To the Golf CourseSuperintendents on the panel, pleaseexplain the topdressing program youuse on your course.

Knapp: At Tuckaway Country Clubwe are presently topdressing our greenswith 100 percent sand. During the first

. year of our program, the greens weretopdressed five times during the year.Now they receive applications duringJune, August and late October. Wehave been applying a total of 20 cubicfeet of sand through the season with theheaviest application in late October.Under our conditions, three heavierapplications seem to do the best job oftruing the putting surface. This is some-thing the golfers want and appreciate,even though there are some complaintsfor a time after the topdressing has beenapplied.

Until this year, we have been using adrop spreader to apply the sand. In 1980we plan to use a centrifugal spreaderbecause of increased efficiency.

After five years of 100 percent sandtopdressing we have noticed a tremen-dous reduction in thatch and a generalincrease and improvement in the waterinfiltration rate of the greens. In fact,last year there was only one day whenwe could not mow after a rainfall. Thisprogram is working well for us.

Berarducci: When I came to SkokieCountry Club two years ago, I inheriteda situation where three different top-dressing mixtures were used. Twelvegreens received a 6-2-2 blend of sand,soil and peat, three greens built toUSGA Green Section specificationsreceived the same 80-20 sandi peatmixture as was their original con-struction blend, and three problemgreens located next to the woods wereon 100 percent sand topdressing. Aftersome study I found that in our situationall three topdressing materials wereunsatisfactory for various reasons.

The 6-2-2 blend created an imper-vious layer on the surface of the greensdue to the high silt content of the mix-ture, and the grass suffered no matterwhat amount we applied.

The 80-20 topdressing material wassupposed to be the same mixture thatthe greens were constructed with origi-

A rotary broadcast spreader in process ofapplying topdressing.

nally, but over the years this material(delivered by an outside supplier)varied to a point that la boratory testingproved it contained unacceptableamounts of silt and clay. This silt andclay formed an impervious suface layerthat caused problems.

Our three greens near the woodsreceived sand topdressing for threeyears and, during this time, one ofthem,a long, uphill par 3 became too firm forthe type of golf shot required to holdthe green. We experienced Poa annualoss over the winter on the second hole,while the third, built entirely of clay,tended to accumulate water duringthe summer in the upper, sandier soilprofile.

These greens, located in shade, werenot well constructed initially, and oursand program simply did not work wellfor us. None of the materials wereentirely satisfactory.

Weare now developing our own top-dressing mixture to achieve what we feelare the properties we want for all greens.We are looking for good infiltrationrate, resiliency and moisture retention.

We feel this can be achieved, under ourconditions, with a laboratory tested70-30 sandi peat topdressing mixture.We believe we now have the right blend.

Moderator: Topdressing programsare designed to meet specific criteria sothere are some differences in top-dressing programs. We will now call onour Green Section Agronomists who, asa result of their concentrated scheduleof Turf Advisory Service visits, observemany topdressing programs.

White: Sand alone has recentlyemerged as the primary topdressingmaterial in the Southeast. Sand top-dressing has been most successful inimproving the rootzone structure and inincreasing the uniformity and play-ability of the playing surface. Wegenerally see light, frequent verticalmowings followed by a light topdressingof approximately Yll to ~ cubic yard per1,000 square feet. This practice encour-ages upright growth, minimizing grainon bermudagrass, bentgrass or winteroverseeded greens.

Hawes: The number of golf coursesuperintendents on a light, frequentsand or high-sand content topdressingprogram similar to that reported byDr. Madison in the May, 1974, issue ofthe GREEN SECTIONRECORD is increas-ing. In the Mid-Continent Region, golfcourses are noted for fast, relativelyfirm greens with decreasing problemsmaintaining good turfgrass on greensthrough the summer stress period. Thisapplies mainly where good materials fortopdressing exist.

Unfortunately, in areas of my region,suitable materials are difficult to find.Quality topdressing materials are expen-sive to import from other parts of thecountry, so the frequency of topdressingis often twice per year in conjunctionwith regular spring and fall aeration.Regrettably, the decisio-n is based pri-marily on costs rather than on soil andagronomic requirements.

Hoos: In the Western Region we see awide variety of topdressing programs.They vary from twice yearly withaeration, to more frequent programs of

MARCH/APRIL 1980 23

applying light amounts of material ontwo- to three-week intervals for a totalof up to 15 to 18 topdressings per yearusing high percentages of sand.

In the arid and semi-arid regions,rainfall occurs only during the winter.This creates a less-than-favorable con-dition for the natural breakdown ofthatch. For this reason, the light, fre-quent topdressing program has beenvery effective in helping to reducethatch by creating better air exchangeand more favorable environment forgood turfgrass growth. The popularityof this program is increasing each year.

Most golf courses that follow thisprogram apply topdressing every threeto four weeks during the active growthperiods. Approximately 1/4 tol/3 cubicyards of topdressing is applied fo:average size greens. The cartster mountedtopdressing machines or rotary fer-tilizer spreaders are the most commonmethods of application.

Many golf courses still use preparedtopdressing mixtures. In the Westernstates, we have a problem finding goodsources of organic matter. Often, decom-posed bark products are used. Manycourses now use a mixture of sand andorganic matter. When organic matter isused, it is best to compost the mix forseveral months before spreading it.

Coupled with the lack of good or-ganic amendments is the lack of qualitysands. Many sands contain too high apercentage of very coarse sand andgravel. These sands do not work into thethatch layer well at all, and they areobjectionable to the players because ofthe need to putt through gravel and tothe golf course superintendents becauseof the need to regrind bedknives fre-quently. I'm sure this is one reason whygolf course superintendents avoid top-dressing if they are forced to use sub-quality material.

Courses using 100 percent sand fortopdressing now pay a premium pricefor high quality sand imported fromother states. Now the standard appli-cation rate is in the neighborhood of1j13 to 1/9 cubic yard per 1,000 squarefeet on a three- to four-week interval.

Snow: In the Northeast, quite a fewclubs use commercial topdressingblends or their own mixtures, rangingfrom 60-90 percent sand with the remain-der made up of soil and peat. These mix-tures vary greatly in quality, especiallythe home-brew blends. We attempt toencourage tests of these mixtures sothat they conform to the Green Sectionspecifications for putting green con-struction. In our position paper on top-

24 USGA GREEN SECTION RECORD

dressing (November, 1977, issue of theRECORD), the Green Section recom-mends that materials used for top-dressing should meet the same vigorousspecifications for soils used in newconstruction because, after all, top-dressing is the addition of a new well-structured soil on top of an existingsoil. Therefore, it is sensible to havethese topdressing mixes correspond tothe same high quality specificationsthat you would use to build a new green.Response has been gratifying, includingreactions from companies that offercommercially blended products thatmeet or very closely match our specifi-cations. This offers the superintendentsa choice of quality materials.

As in other regions, topdressing withsand is becoming increasingly popular.As with any topdressing, these sandsneed testing to make certain they fall inthe proper particle size ranges. This canbe done locally or at a nominal chargethrough our USGA soil testing labora-tory at Texas A&M University, SoilPhysics, Soil and Crop Sciences Depart-ment, Texas Agricultural ExperimentStation, College Station, Texas 77843.We are fortunate in our area to havemany good sands available, usually atreasonable cost.

Moderator: Up to now we've talkedabout topdressing mostly in positiveterms. When have you seen topdressingnot work well?

Hawes: We sometimes see it in Kan-sas, in the spring when the fields arebeing worked and it is windy. Naturetopdresses the greens with a silty wind-blown material forming a problem layeron the putting green surface. One coursewe know improved its problem byreducing the cultivations of adjacentfields and erecting a hedgerow as awindbreak.

Berarducci: In my case, too much siltand clay was in our topdressing mix-tures. This created a surface layer prob-lem. Where the sand was used on one ofmy clay-based greens, there under-standably arose a situation where toomuch water began to accumulate at thesurface. This should correct itself intime as more quality topdressing IS

applied.Snow: When the wrong material is

used, when there is too much silt andclay in the mix, when too coarse a sandis used, when topdressing is applied tooheavily or infrequently, when topdressingmixes are continually changed; theseare examples where topdressing willwork against you.

White: Tifdwarf bermudagrass willnot tolerate heavy applications of top-dressing as well as Tifgreen will. There-fore, a more controlled program mustbe exercised on those courses growingTifdwarf.

With the tremendous differences insand sources, it is important to have thesand laboratory tested. The wrong sandwill cause problems.

Knapp: The principal negative aspectof my sand program is the slow recoveryof greens damaged by vandalism orwinter injury. Seed germinates veryslowly in a high sand topdressing due toits low moisture retention capacity. Weuse sod now to repair such damage.

Hoos: Let me add that the amount oftopdressing that is applied shouldmatch the growth rate of the grass,always striving to maintain enoughcushion to reduce the impact of wear onheavily played greens.

Moderator: What do you all feel isthe future of topdressing in the 80s?

Knapp: In the 1980s I feel the futurelooks bright for sand topdressing.When good high-quality tested sandsare used, the overall greens maintenanceprogram can be simplified and yet stillgive the golfers a fine playing surface.

Hoos: I believe more and more golfcourse superintendents will adapt anduse the light frequent technique ofapplying topdressing and will moveaway from the old practice of heavyapplications in conjunction with aer-ation, even though this practice is stilleffective on some golf courses. As pesti-cide and fertilizer costs escalate, moreemphasis will be placed on managementprograms that get the maximum bene-fits from the material used. Topdressing,with its recognized benefits in disease,insect and weed reduction will be a partof future programs. The major draw-back in the West may be in findingsuitable materials at a reasonable cost.If they were more readily available, I'mcertain that Western courses wouldtopdress more frequently.

Hawes: I agree that the future oftopdressing is bright where good top-dressing materials are available. Thesuccessful programs that have beenproperly carried out are well-docu-mented. As new, more efficient methodsof applying topdressing are used, moresuperintendents will be encouraged touse topdressing more frequently.

White: As renovation and rebuildingcosts escalate, topdressing to amendproblem soils should remain popular.

Preferred sand to use for topdressinggreens - with particle size distributionranging from 0.11 mm to 1.0 mm.

A time and labor saving method of fillingthe spreader.

S oil amendment through topdressingcan be effective over a period of years,but it can never be as effective as totallyrebuilding a poor rootzone.

Snow: In the future, we should knowmore about the long-term effects, if any,of straight sand topdressing. Everyattempt should be made to use a testedsand that meets USGA specificationsfor particle size distribution and infil-tration rate, preferably one that con-tains a small percentage of silt and clay.Apply it lightly and frequently, andnever again go back to a heavier type oftopdressing material.

Berarducci: Topdressing should con-tinue to be an important part of pro-gressive golf course management in the80s when playability and soil needs aretaken into account. The information onwhat to use is available. The turf mana-ger must decide which topdressing willperform best on his course, then use itwisely. It is a decision that requires a lotof study.

Moderator: Thank you panelists foran interesting and informational dis-cussion of "Topdressing Putting Greens."

NOW AVAILABLE

A Literature Review on SewageUtilization for Turfgrass Purposeswith Annotated Bibliography

byA. E. Dudeck and C. E. DonohoOrnamental Horticulture DepartmentInstitute of Food and Agricultural

SciencesUniversity of FloridaGainesville, Florida 32611

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A. J. Turgeon, P. L. Heinzen,and G. E. Stout

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University of IllinoisUrbana, Illinois 61801

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Financial support by the American Soci-ety of Golf Course Architects and the ToroCompany through the USGA Green SectionResearch Fund made this Literature Reviewpossible.

MARCH/APRIL 1980 25