Nevada C-10 Landscape Contracting Examination

Under NAC 624.280, which work is inside the Nevada C-10 landscape contracting classification?

• AGrading plots for architectural horticulture and installing landscape irrigation
• BInstalling a 120-volt patio receptacle circuit
• CBuilding a load-bearing concrete driveway approach
• DConstructing an engineered swimming pool

Before excavating planting pits, irrigation trenches, or a French drain, what must the C-10 crew do first?

• ACall 811 and wait for utility marks
• BOrder all plants so they can go in the same day as digging
• CSoak the site overnight so the soil is easier to shovel
• DCut all existing tree roots that are in the way

What is the first design task on a new residential landscape after the contract and utility locate are in place?

• APerform a site analysis of sun, wind, slope, soil, drainage, and existing vegetation
• BOrder every plant on the wish list at mature size
• CSet all irrigation heads before the planting plan exists
• DImport 12 inches of potting mix over the entire lot

Why should a C-10 planting plan group plants into hydrozones?

• ASo plants with similar water need, sun, and soil can be irrigated together
• BSo every plant on the lot can share one spray zone
• CSo the contractor can skip a backflow preventer
• DSo turf and cactus can be mixed on the same rotary zone

A complete C-10 construction set for a custom yard should include which drawing set?

• AA scaled layout with planting schedule, irrigation plan, and finish-grade or drainage not…
• BOnly a plant photo collage with no dimensions
• CA business-license photocopy taped to the permit board
• DA freehand sketch with no north arrow or scale

Which proposed structure is outside C-10 scope even if it is in a planted yard?

• AA site-built engineered trellis designed as a load-bearing shade structure
• BA nonengineered prefabricated arbor from the manufacturer’s kit
• CA decorative dry creek of cobble and sand using xeriscape materials
• DA hydroseeded slope with tackifier and mulch

On a Las Vegas lot, which microclimate usually needs the most heat- and drought-tolerant plant palette?

• AA west-facing wall that reflects late-day sun onto the planting bed
• BA north courtyard shaded by the house all afternoon
• CA covered patio with only morning light
• DThe north side of a two-story house

Finish grade next to a house slab should do which of the following?

• AFall away from the foundation, commonly about 6 inches in the first 10 feet where the lot…
• BSlope toward the foundation so planting basins stay full
• CBe perfectly flat so irrigation water ponds evenly against the stem wall
• DBe built up against siding to hide the stem wall

A homeowner wants one C-10 bid for all of the following. Which single item forces another classification or an engineer?

• ADrip conversion of existing shrub beds
• BA 3-foot landscape retaining wall with gravel backfill
• CA 24-volt path-light circuit on a listed transformer
• DA 5-foot site-built masonry wall that will hold a driveway surcharge

What does “grade and prepare plots for architectural horticulture” mean on a C-10 job?

• AShape planting areas, set finish grades, and prepare soil for designed plantings
• BRough-cut a county road alignment to subgrade
• CInstall underground electrical primary
• DPour structural footings for a new house

A client wants a shade structure over a patio. Which option can a C-10 contractor install under NAC 624.280?

• AA nonengineered prefabricated arbor assembled to the manufacturer’s instructions
• BA welded steel pergola designed by the contractor as a roof structure
• CA site-built stick-framed patio cover tied into the house roof
• DA two-story trellis used as a second-floor deck guard

You are reviewing a C-10 plan before mobilization. Which combination is the most serious design defect?

• ATurf spray, desert shrubs, and a vegetable garden all drawn on one irrigation valve
• BA plant schedule that lists both botanical and common names
• CA note to call 811 before trenching
• DA drip detail showing a filter and pressure regulator

Which soil texture drains fastest and holds the least plant-available water?

• AClay
• BSilty clay loam
• CSand
• DClay loam

What is caliche, a layer often found when planting in Southern Nevada?

• AA cemented calcium-carbonate hardpan that blocks roots and drainage
• BA layer of decomposed granite used as mulch
• CA manufactured soil amendment high in peat
• DA type of drip emitter

University of Nevada Extension advises which simple drainage check before planting a tree?

• AFill the hole half full of water; if it is still standing after about 12 hours, pick anot…
• BPour a cup of water on the surface and plant immediately if it beads
• CAssume all desert soils drain in under 10 minutes
• DSkip the test whenever caliche is visible

A lab report shows a sodic (high-sodium) landscape soil. Which amendment is the usual chemical treatment?

• AElemental sulfur only, with no calcium source
• BStraight table salt to raise soluble salts
• CAgricultural gypsum (calcium sulfate) to help displace sodium
• DUsed motor oil to waterproof the clay

How should compaction be handled differently under a paver patio versus in a planting bed?

• ACompact both to the same structural density so nothing settles
• BLeave the patio base uncompacted and compact only the plant pits
• CCompact the patio base for support; keep planting-bed soil loose enough for roots and inf…
• DFlood both areas overnight instead of using a compactor

What is the correct basic assembly for a landscape French drain?

• ASolid pipe laid flat on native clay with no gravel
• BPerforated pipe pointed uphill so water is stored in the trench
• CSloped trench, clean gravel, perforated pipe, and filter fabric, discharging to a legal o…
• DA hose laid on the lawn surface after each storm

After rough grading a front yard, the finish grade at the house is level with the slab for 12 feet. What should the C-10 contractor do?

• ALeave it; desert rain is too rare to matter
• BBuild a watering basin against the stem wall for the foundation shrubs
• CReshape the first 10 feet to fall away from the foundation, about 6 inches if the lot all…
• DInstall spray heads that throw onto the slab to wash it

A French drain will run 50 feet from a low planter to a sidewalk outlet. Using about 1 inch of fall per 10 feet, how much total drop is required?

• A1 inch
• B2 inches
• C5 inches
• D24 inches

What is hydroseeding as defined for C-10 work?

• ABroadcasting dry seed by hand with no mulch
• BInstalling sod with a carpet knife
• CSpraying a slurry of mulch, seed, and nutrients under pressure
• DInjecting fertilizer into a potable-water main without backflow protection

Where should a silt fence be installed on a disturbed landscape lot?

• AAlong the uphill property line so it stays clean
• BAcross the ridge line as a windbreak only
• CDownslope of the disturbed soil, trenched in, to intercept sediment before it leaves the…
• DOn top of the sidewalk after the soil has already washed off

A 3:1 (horizontal:vertical) landscape slope will be hydroseeded. What erosion-control measure belongs on the face until vegetation knits?

• AA rolled erosion-control blanket or bonded fiber matrix/tackifier suited to the slope
• BSmooth, sealed plastic sheeting that sheds all water onto the sidewalk
• CNo cover, because desert rain never moves soil
• DA solid concrete veneer required on every 3:1 landscape slope

A new mesquite is planted in a pit blasted through caliche. The pit holds irrigation water for two days. What is the correct diagnosis and fix?

• AThe tree wants more frequent spray irrigation
• BAdd peat moss until the water disappears
• CThe pit is a sealed bathtub; provide drainage or raise the root ball and do not drown the…
• DBackfill with pure compost to soak up the standing water

During site stripping, what should be done with existing topsoil that will be reused?

• AMix it into structural fill under the patio base
• BHaul it all off because desert topsoil has no value
• CStockpile it separately for later respread on planting areas
• DUse it as pipe bedding under the irrigation main

Per University of Nevada Extension, how wide and how deep should a tree planting hole be?

• AAs deep as possible and only as wide as the container
• BTwice as deep as the ball and half as wide
• CTwo to three times the root-ball width and no deeper than the root-ball height
• DExactly the container diameter and 12 inches deeper

Where should the root flare sit after a tree is planted?

• ASeveral inches below finished grade and hidden by soil
• BEighteen inches above grade on a pedestal of gravel
• CVisible at or slightly above finished grade
• DBelow a volcano of mulch piled against the trunk

What mulch practice does UNR Extension specify around a newly planted Nevada tree?

• A2 to 3 inches of organic mulch, kept at least 2 inches away from the trunk
• B8 to 10 inches of mulch piled against the bark for insulation
• CNo mulch, so the soil can bake and sterilize weeds
• DA sheet of impermeable plastic under decorative rock against the trunk

A container tree has circling roots at the pot wall. What should the planter do?

• APlant it as-is so the root ball stays intact
• BBend the circling roots into a tighter spiral
• CTease or cut circling roots and score the sides so new roots grow outward
• DPlant the pot and all so roots are never disturbed

When setting a large balled-and-burlapped tree, what should be done with the wire basket and burlap?

• ALeave all wire and burlap intact forever so the ball cannot break
• BRemove the soil from the ball and plant it bare-root in summer heat
• CAfter the tree is set, remove at least the top one-third to one-half of the wire and burl…
• DCover the entire basket with extra soil so nothing shows

In Nevada, when is the preferred season to plant landscape trees?

• AMidsummer when temperatures are in the 90s F and above
• BAny day the nursery can deliver, with no seasonal preference
• COnly during monsoon week in July
• DFall and early winter, when soil is still warm and transplant stress is lower

Should a newly planted Nevada landscape tree be fertilized in the first growing season?

• AYes, with a high-nitrogen stake against the trunk
• BOnly if the flare is buried
• CYes, weekly liquid feed at label triple rate
• DNo. Avoid fertilizer the first season so the tree can establish roots; compost as mulch i…

When staking is required, how should a Nevada landscape tree be staked?

• AOne rigid post lashed tight to the trunk for five years
• BFour steel cables to nearby buildings
• CWire wrapped directly around the trunk at 6 feet
• DTwo stakes outside the hole, flexible ties below the lowest branch, allowing some movemen…

A client wants a large shade tree under existing power lines. What is the correct plant-selection decision?

• APlant the largest shade tree available and top it every year
• BIgnore the lines because the utility will always relocate them
• CPlant a palm because palms never need clearance
• DChoose a species whose mature height fits under the lines, or pick another site

Why does UNR Extension warn against making a planting hole “too rich” with amendments?

• ARich soil always kills desert plants on contact
• BNative soil must never be reused as backfill
• CAmendments are illegal in Nevada landscapes
• DA hole much richer than the native soil acts like a virtual pot and discourages roots fro…

Compared with a cool-season lawn, a low-growing desert groundcover is used mainly to do what?

• AReplace every tree on the lot
• BSubstitute for a compacted paver base
• CEliminate the need for any irrigation forever on day one
• DCover soil, reduce erosion and heat, and use less water than turf

Which turf choice matches Southern Nevada’s hot low-desert climate better than a high-elevation northern-Nevada lawn?

• AKentucky bluegrass as the only species in Las Vegas
• BAnnual ryegrass as a permanent summer lawn
• CCreeping bentgrass putting-green turf in full west exposure
• DBermudagrass, a warm-season turf used in the low desert

What is a girdling root?

• AA beneficial root that ties the tree to a stake
• BA mycorrhizal filament on desert shrubs
• CAny root deeper than 12 inches
• DA root that circles and constricts the trunk or other roots, cutting vascular flow

UNR Extension says most trees do not like “wet feet.” If a test hole still holds water after 12 hours, what is the correct action?

• APlant a water-intolerant desert tree anyway and hope
• BInstall a spray zone in the bottom of the hole
• CAdd a high-nitrogen fertilizer to dry the hole
• DChoose another location or correct drainage before planting

When a new tree is placed on drip, UNR Extension recommends which emitter layout?

• AA single emitter on the uphill side only
• BA full-circle spray head in the watering basin
• COne mister aimed at the trunk flare
• DAt least four emitters around the tree so roots grow in all directions

What is the U.S. formula for sprinkler precipitation rate in inches per hour?

• APR = 96.3 × GPM ÷ area (sq ft)
• BPR = GPM ÷ 96.3 × area
• CPR = area ÷ GPM
• DPR = psi × 2.31

A turf zone applies a total of 6.0 GPM over 600 square feet. What is the precipitation rate?

• A0.16 in/hr
• B3.85 in/hr
• C1.60 in/hr
• D0.96 in/hr

A 5-gallon bucket at the hose bib fills in 15 seconds. What is the available flow?

• A5 GPM
• B10 GPM
• C15 GPM
• D20 GPM

Available flow at the point of connection is 18 GPM. A proposed turf zone has eight spray heads at 2.5 GPM each. What should you do?

• AInstall all eight heads on one valve; 20 GPM is close enough
• BClose the backflow preventer halfway to raise pressure
• CAdd four more heads to balance the pressure
• DSplit the heads onto two valves or reduce nozzle flow so zone demand stays below 18 GPM

What does head-to-head coverage mean?

• AEach head’s throw reaches the adjacent heads
• BHeads are aimed only at the sidewalk
• COne head in the center waters the whole yard
• DHeads are spaced at twice their listed radius

A full-circle nozzle on a matched-precipitation set flows 4.0 GPM. What should the half-circle nozzle on the same zone flow?

• A0.5 GPM
• B8.0 GPM
• C4.0 GPM
• D2.0 GPM

Why should spray heads and gear-drive rotors not share the same valve?

• AThey use different thread colors only
• BSprays are illegal in Nevada
• CRotors cannot operate on potable water
• DTheir precipitation rates differ by a factor of about two to four, so run time cannot be…