Planting, Turf, Pruning, and Maintenance
This chapter covers installing plants correctly, establishing turf, and the Maintenance and Repair content area that CSLB lists separately at about 11 percent of the examination, which includes pruning, tree removal, and integrated pest management. Planting details are where a landscape either succeeds quietly for twenty years or declines visibly in three, and the specific dimensions and practices below are the ones the exam tests.
Planting Depth, Hole Geometry, and Backfill
Three planting details account for most avoidable tree and shrub failures. First, depth. The top of a container-grown root ball is set at or slightly above the surrounding grade, and on a tree the root flare, the point where the trunk widens into the roots, sits at or slightly above finish grade. Planting too deep buries the flare, keeps the bark constantly moist, and slowly kills the plant, which is why a shrub planted three inches too deep two years ago and now declining is corrected by excavating the excess soil back to expose the root crown. Second, hole geometry. The planting hole is dug two to three times as wide as the root ball, and only as deep as the ball, because the purpose of the width is to give new roots loosened soil to spread into laterally, which is where roots grow, while a hole dug deeper than the ball settles and drops the plant. Third, backfill. Current practice is to backfill with the native soil that came out of the hole rather than a rich amended mix, because a pocket of amended soil in native ground creates a texture interface that discourages roots from leaving the hole and can hold water like a container. Handling matters at delivery. A five-gallon shrub whose roots circle tightly around the outside of the root ball must have those circling roots scored or teased apart before backfilling, or they will girdle the plant as they thicken. A balled-and-burlapped tree in a wire basket with synthetic burlap is set in the hole first, and then the upper portion of the wire basket and the synthetic burlap are cut away, since synthetics never decompose. A bare-root rose arriving in January is kept with its roots moist and shaded and planted while still dormant. Staking is temporary and deliberately loose: ties are placed low on the trunk, movement is allowed so the trunk develops taper and strength, and the stakes come out within about a year.
Plant Selection, Spacing, and Site Fit
Spacing is set by the mature size and spread of the species, not by how the bed looks on installation day, and a foundation planting spaced for immediate effect becomes an overgrown hedge that must be sheared forever. Spacing geometry also changes plant counts. Groundcover specified at 18 inches on center in triangular spacing uses more plants than square spacing at the same interval and closes the bed more evenly, because triangular spacing eliminates the diagonal gaps that square spacing leaves. Site fit questions come up repeatedly on the exam because they come up repeatedly in practice. A 40-foot shade tree placed eight feet from a two-story wall on the south side will put its mature canopy and roots in conflict with the structure. Turf specified under the canopy of dense mature trees on the north side of a building is a poor fit because of shade and root competition, and the contractor should raise it with the designer rather than install it and warranty it. In most of California, fall gives the best establishment for woody landscape plants, because the soil is still warm enough for root growth and the winter rains follow, giving the plant months to establish before summer heat. For water efficiency, the defensible approach on a plant list is to select species by regional water use ratings and then group them by need, which is hydrozoning again, and it is what MWELO's plant factor calculations depend on. Existing trees are protected during construction by fencing placed at or beyond the drip line of the canopy, because that is roughly where the feeder roots are. Two grading actions are particularly damaging near a preserved tree: placing a foot of fill over the root zone smothers roots by cutting off oxygen exchange at the surface, and cutting grade severs them. Where a patio must be built over the root zone of a preserved tree, the protective approach is a pier-supported deck or a permeable surface set on grade rather than excavation and a slab.
Turf Selection and Establishment
California uses both cool-season and warm-season turfgrasses, and the distinction drives everything else. Cool-season grasses such as tall fescue grow most actively in the cooler temperatures of spring and fall and stay green through winter. Warm-season grasses such as hybrid bermudagrass grow in summer heat, take heavy wear, and go dormant and brown in winter, which is why a full-sun sports lawn in the Central Valley is well served by hybrid bermudagrass and why that lawn is overseeded with perennial ryegrass in October, to provide green cover while the bermudagrass is dormant. Establishment method is a cost and time trade-off. Seeding costs the least in materials and takes the longest to cover, and it demands careful watering, because germinating seeds and shallow new roots die quickly if the seedbed dries even once; that is why a seeded area is scheduled with brief cycles several times a day during establishment. Sod costs more and covers immediately. Sod is laid on a prepared grade with the joints staggered in a running bond and the edges butted tightly so no gaps open as the pieces shrink, and it is rolled lightly and watered immediately after installation to bring the roots into contact with the soil and prevent drying. Hydroseeding sits between the two, and a slope mix typically includes seed, fertilizer, wood fiber mulch, and a tackifier, where the tackifier binds the slurry to the slope so it resists rain and wind before the seed germinates. Two maintenance practices belong with turf. The one-third rule requires that no more than one third of the leaf blade be removed at any single cutting, because removing more shocks the plant and forces it to draw on reserves. And core aeration, which removes plugs of soil and opens the profile, is the practice that most directly relieves a heavily used lawn that drains poorly and feels hard underfoot. Converting a lawn to a low water use planting has one preparation step that most affects long-term success: killing or removing the existing turf and its rhizomes completely, because bermudagrass and similar grasses regenerate from rhizome fragments and will invade the new planting for years.
Pruning and Tree Work
Pruning cuts are made in a specific place for a specific biological reason. The final cut when removing a limb is placed just outside the branch collar, the swollen ring of tissue where the branch meets the trunk, because the collar contains the tissue that grows over and seals the wound; cutting flush to the trunk removes that tissue and leaves a wound the tree cannot close, and leaving a long stub leaves dead wood that decays back into the trunk. Heavy limbs are removed with the three-cut method: an undercut a foot or so out from the final cut, a top cut slightly beyond it that drops the limb, and then the final cut at the collar on the remaining stub. The purpose of the first two cuts is to prevent the falling limb from tearing a strip of bark down the trunk as it goes. Topping a tree, cutting large limbs back to stubs to reduce height, is not an accepted practice; the professional response to a client who asks for it is to decline topping and offer crown reduction back to appropriate lateral branches, which reduces size while leaving the tree a structure it can heal and regrow from. The general limit on live crown removal in a single season is no more than about a quarter of the canopy, because the leaves are the tree's food production and removing too much starves it. Tree work is also the most dangerous work a landscape crew does. A climber working aloft on rope relies on a rope, saddle, and secure tie-in point for fall protection, and the essential principle is that the climber remains tied in on a properly rigged system at all times aloft. Limbs within ten feet of an energized overhead distribution line are not a landscape crew's work at all: stop and arrange for qualified line clearance tree trimmers, who are trained and equipped for that clearance. Pruning from an elevated work platform at 12 feet requires a body harness with a lanyard attached to the platform's anchor point.
Integrated Pest Management and Weeds
Integrated pest management is a decision sequence, not a product: monitor first, identify the organism, decide whether the damage justifies action, use the least disruptive effective control, and preserve the natural enemies that are doing free work for you. So when an aphid population appears on a hedge with lady beetles already present, the reasonable first action is to monitor and wash the aphids off with water, preserving the predators, rather than spraying an insecticide that would kill the lady beetles and guarantee a worse outbreak next month. Correct identification depends on reading the symptoms as a sequence. Sticky residue and a black sooty coating on leaves under a tree means sap-feeding insects such as aphids or scale are excreting honeydew and a mold is growing on the honeydew, so the target is the insect, not the mold. Fine stippling and light webbing on shrubs beside a dusty driveway during a hot dry spell points to spider mites, which increase in hot, dry, dusty conditions and are often made worse by broad-spectrum sprays that kill their predators. An arborist reporting Armillaria root disease in a bed where oaks are declining gives the C-27 contractor a specific job: reduce summer irrigation near the trunks and improve drainage, because the disease is favored by warm, wet soil against the root crown. Weed control has its own timing rule. A pre-emergent herbicide must be applied before weed seeds germinate and then watered in to form a barrier in the surface soil; applied after emergence it does nothing to the weeds already growing. Bermudagrass invading a shrub bed from an adjoining lawn spreads by rhizomes and stolons, so the durable control combines a physical edge barrier with systemic control of the rhizomes; edging alone will not stop it and a contact herbicide only burns the tops.
Last updated: September 2026