The finished job.

Need Insurance? HydromulchingIs One Good Policyby PATRICK M. O'BRIENDirector, Southeastern Region, USGA Green Sectionand ROBERT BARKSDALE, Landscape Supply, Virginia

A:RICULTURE HAS always beena risky business, but in recent

years, every business has becometremendously more risky as insurancehorror stories go on and on. Not solong ago Time ran a cover story "Sorry,America, Your Insurance is Cancelled."Everyone is affected and everyone ispaying more and more for this litigioussociety.

That said, it's nice to know there arestill some things in life that are relativelysimple and easy to understand. Thereare still some things we can do to protectan investment and to ensure success. Forexample, if you are going to seed somenew greens, or a golf course, or hillsides,or even wildflower areas, there's aninsurance policy you should know about.It's called hydromulching!

Hydromulching got its start in theearly 1960s when state highway depart-ments learned that mulch was an assetin establishing grasses quickly andeconomically on non-irrigated hillyterrain. The protective mat provided afavorable micro-environment for seedgermination and growth while alsoprotecting the seed, fertilizer, and topmix from wind and rain erosion.

Historically, a light straw mulch hasbeen used on golf greens for a long timeto stabilize the soil and to gain improvedgermination. Straw or some similarmaterial is applied by hand over theentire green surface immediately afterseeding. It isn't an easy job, particularlyin determining the proper thickness andin applying the material uniformly. Ofcourse, once germination takes place,

the straw cover has to be carefullyremoved and in a timely manner toavoid both disease and smothering theyoung grass. The straw frequently con-tains weed seeds, which contaminatethe green. Under high winds, it can beblown away. For all of these reasons,it is rarely used today.

Hydromulching is becoming moreand more popular. With the currentshortage of bentgrass seed and witharchitects designing greens with moreundulations and contours, hydromulch-ing takes on new importance. Hours ofcareful labor and expensive seed, soil,and fertilizer can be washed away by asudden storm, irrigation malfunction,or high winds. Not only is repair, re-grading, and reseeding expensive, butany delay in the construction schedule

JANUARY/FEBRUARY 1987

has incalculable consequences. Fieldexperiences also show hydromulchingincreases total seed germination, be-cause evaporation rates and soil moisturelevels are better controlled. These con-siderations increasingly assume prece-dence over the extra costs of hydro-mulching applications.

The practice of hydro mulching greensis becoming especially prevalent alongthe Atlantic seaboard and in the South-east in the fall. It is a good tool to helpensure fast, uniform turf establishment,particularly on sandy soil mixes. Thesetend to dry out, and hydromulchinghelps hold some moisture for the newseed. Clubs seem interested in this kindof insurance, because it frequently paysdividends in the form of saved labor andtime.

HYDROMULCHING, fortunately,need not be a significant cost

factor, since the process doesn't requiremuch labor or equipment. However,several points should be consideredbefore taking out this insurance policyon your course:

1. Applying hydro mulch to a puttinggreen is an art. The most importantvariable is a skillful operator. Not alloperators have the knack to do the jobcorrectly and to apply the proper amountof material.

2. Although hydro mulching materialsare much improved, no mulch is perfect.All mulching materials are subject tomovement in the event of heavy rains.The chances of erosion are significantlyless, however, if the proper hydro-mulching technique is followed.

3. The putting green area should beseeded and fertilized prior to the hydro-mulching operation. Bentgrass seed istoo small to be included in a tankmixture with the mulch. The mulchitself may tie up the seed and germi-nation will occur in the mulch layerinstead of in the soil. Seed contact withthe soil is important for the highestpercentage germination.

4. The germination rate will be fasterand more uniform by lightly rolling thesurface after seeding and before hydro-mulching. The purpose of rolling is tofirm the surface. When the mulch isdegraded and mowing begins, smooth-ness will be significantly better.

Selecting a good operator for yourhydro mulching job is a most importantstep. Most golf courses hire an outsidecontractor for both his experience andmachinery. Seldom is this work doneby the golf course crew. The hydraulicmulcher is the basic piece of equipment.

2 USGA GREEN SECTION RECORD

1

(Above) Straw or, in this case, palm leaves were used in years past as acover for new seed. (Top) The paper mulch is compressed and very drywhen loaded into the tank. (Opposite page, top) Applying mulch witha hose operated by a remote valve. (Bottom) Most paper mulches are

recycled newspapers or corrugated cardboard.

It is a fairly simple unit with an agitationsystem for mixing and keeping the mulchin suspension, a pump with a gun forapplication, and a gasoline engine topower the agitator and the pump.

An experienced operator will alwaysclean the tank as a first step. Too oftenthe hydraulic mulching equipment hasbeen used previously for a highwayroadside development, private or com-mercial real estate sites, or park con-

struction. These jobs use grasses andfertilizers that are undesirable for golfcourses, especially putting greens. Fillingthe tank with water and dischargingthrough the nozzle is always a goodidea.

Once the tank is clean, it is importantto prepare the mix properly. A goodoperator will always preside over thetank-filling operation. To start, the tankis loaded half full of water. Usually of

at least 500-gallon capacity, the tank istrailer-mounted and pulled behind atractor or truck. The mulch is addedthrough the loading hatch while thetank continues to fill with water, and itis thoroughly mixed with the water byagitation in the tank. If too much mulchis added, the nozzle might clog.

A nozzle is selected to produce a finemist, not a coarse spray. The pump isgenerally set at full pressure (100-150 psi)to maximize the shooting range (30-50feet). With a fine mist nozzle and properpump speed, a uniform application ofmulch mat can be applied.

Once the load is prepared, the operatoris ready to "shoot"the green. The mulchis applied either from a tower-mountedgun on the tank, or for even bettercontrol, through a hose and a remotevalve. An experienced operator knowsexactly how much mulch to apply overa new putting green, all the while con-sidering wind direction and speed. Theoperator can visually meter his patternand rate by the color and the thicknessof the mulch. Mulches contain a water-soluble, harmless green dye for appli-cation and aesthetic purposes. The coloreventually disappears as the mulchdecomposes. If the operator applies toomuch mulch, the soil surface may besealed. This impedes the seedlings'growth. The goal is to apply just enoughmulch so that a degree of anchoring andprotection is produced for the seedwithout having it buried.

JANUARY/FEBRUARY 1987 3

TABLE 1.

A Few Selected Commercial Paper and Wood Fiber Mulches

SEVERAL MULCHING materialsother than straw. are available for

golf .courses today. Paper products orground wood fiber are the most popular.The first paper mulch was produced in1961. Most paper mulches are recyclednewspapers, corrugated cardboard, ormagazine paper. Those derived fromnewspapers or corrugated cardboardare considered to be the best. The cor-rugated cardboard source has longerwood fiber, offering more stability andprotection for the seed. A paper mulchwill contain no germination- or growth-inhibiting substances. It is also weedfree. The application rate is 1,000 to1,500 pounds per acre over bentgrassseed. The higher rate is advised for moreundulating greens. More than ten dif-ferent commercial brands are availabletoday (Table 1).

The wood cellulose mulch deriveddirectly from a natural wood source isanother form of wood cellulose fiber.It has the advantage over paper mulchesby being even more effective on poten-tially high-erosion areas. However, theseare significantly more expensive and thegently sloping terrain of most puttinggreens does not justify the extra cost.If a wood cellulose mulch is selected,the application rate is 10 to 20 percentless to achieve the same results as apaper mulch.

There usually is not a tackifier orsticker-type material included with themulches. These erosion-control agentsare usually purchased separately andadded to the mulch, although somemanufacturers offer mulches with atackifier. The water-insoluble tackifierIS added to the tank at the rate of 5

Brand Name

1. Cellin Mulch2. Cellin Plus3. Cellin K4. Cellin K Plus5. Super South6. Spray Mulch7. Weyerhauser8. Sunlock9. Terra Mulch

10. Hydro-Loc11. Conweb12. Conweb 2000

Type

Ground NewspaperGround NewspaperGround CardboardGround CardboardGround NewspaperGround MagazineGround Card boardGround NewspaperGround NewspaperGround NewspaperWood Fiber MulchWood Fiber Mulch

Ingredients

Wetting Agent and DyeWetting Agent, Dye, and TackifierWetting Agent and DyeWetting Agent, Dye, and TackifierWetting Agent and DyeWetting Agent and DyeWetting Agent and DyeWetting Agent and DyeWetting Agent and DyeWetting Agent and DyeWetting Agent and DyeWetting Agent, Dye, and Tackifier

gallons per 500 pounds of mulch. Thisingredient is very important not only inholding the individual mulch fiberstogether, but also allowing them to holdmore tenaciously to the putting greensurface, particularly on greens withsevere undulations. This helps to createa more crusty surface that is less suscep-tible to erosion from excess water. Ifsite conditions are ideal and excessivemoisture is not expected, a tackifier isunnecessary.

A wetting agent is also mixed into allpaper and wood cellulose mulches,enhancing the flow of the mulch fromthe tank through the nozzle. The wettingagent reduces the surface tension of thewater, so the mulch slurry will passthrough the equipment better. Further-more, many of the mulches are com-pressed into a bale for packaging pur-poses, and the addition of a wettingagent helps wet the paper and woodmulch chunks as they are loaded intothe mixing tank. The manufacturersremove as much of the moisture fromthe mulches as possible for easier ship-ping. Consequently, the material enteringthe tank is usually very dry.

Once the mulch is applied, all thatremains is to keep it moist throughbentgrass establishment. Less waterthan usual is needed during the germi-nation stage since the evaporative waterloss from the soil surface is reduced.Most mulches reduce the syringefrequency from four to five times a daydown to one or two times.

The bentgrass seeding rate for greensis 1.5 pounds per 1,000 square feet. Mostsuperintendents have noted germinationin four to five days after hydromulching,

whereas bentgrass usually germinatesin seven to ten days in favorable weatherwithout hydromulching. A uniform turfcover is usually achieved in four to fiveweeks, using less seed with a highergermination yield encouraged by theproperly applied mulch.

Since the sand in the upper profile isstabilized sooner using a mulch, puttinggreen mowers pick up less sand with thefirst mowing, which reduces the needfor extra lapping on the mowers.

WHAT IS THE COST of this in-surance? If it is figured on a per-

acre basis, actual mulching costs arenot great. Paper mulches range from$200 to $240 per acre, while the woodcellulose mulches cost between $300 to$340 per acre. If a tackifier is added tothe tank mixture, there is an additional$50 to $60 per acre. It is usually just aseconomical to purchase a paper or woodmulch with a tackifier than to add thetackifier separately.

A contractor usually charges $500to $700 per acre for renting the equip-ment and applying the mulch. The big-gest variable in the cost is how far thecontractor must transport his equipmentto the site. In most instances, the totalcontracted cost is between $2,000 and$3,000 for 18 putting greens. Thiseq uates to a range of $110 to $170 pergreen. Expensive? Well, since the basicconstruction cost of most new puttinggreens today is $25,000 or more, this isless than 12 percent of the total cost. Itseems worth the expenditure.

Because of economic needs or mem-bership requirements, many golf coursesmust seed their new greens later in thegrowing season than desirable. Thisneed to stretch the normal seedingseason is met to a large degree byhydromulching. The mulch has a buffer-ing effect on the soil temperature inthe upper profile. It keeps the soilwarmer later into the fall, and it willalso protect the new seedlings duringhigh summer temperatures.

Hydromulching is a useful tool worthconsideration by golf courses planningto build or reconstruct putting greens.It helps establish bentgrass more uni-formly, and it protects against seedmovement. It saves labor and time. Theshort supply and high cost of bentgrassseed, not to mention the benefit ofreduced irrigation, uniform establish-ment with faster and higher germinationrates, and reduced erosion possibilities,makes hydromulching a valuable tool insuccessful putting green establishment.It is a proven management technique.

4 USGA GREEN SECTION RECORD