CA Landscape common mistakes
CA Landscape · Understand the traps and how to avoid them.
Scales dimensions off the printed plan without checking the scale bar on that specific sheet, or mixes up units mid-calculation (cubic feet of amendment converted to cubic yards, tons of aggregate versus cubic yards, square yards of Sod).
Candidates memorize '1/8 in = 1 ft' from one sheet and assume every sheet in the set matches; reduced or enlarged prints and sheets marked NTS then produce answers that are off by a fixed factor, and unit slips survive to the final answer because the arithmetic 'looks right'.
What to do instead
Before any takeoff, locate the graphic scale bar on the printed sheet and confirm it against one dimensioned line. Do takeoffs from dimensioned figures first and only scale as a cross-check. Keep a one-page conversion table (1 CY = 27 CF, 1 acre = 43,560 SF, 1 ton aggregate ≈ 0.6–0.7 CY) and write units on every line of the calculation.
Bids only from the plan sheets and skips the specifications, general conditions, and note blocks, so exclusions, allowances, staging restrictions, and demolition/export items never enter the price.
Plans are visual and feel like 'the job'; specs and notes are dense text and get skimmed under time pressure, and it is easy to assume the exam question is asking only about the drawing.
What to do instead
Read the written specifications and general notes before opening the plan sheets, then build a checklist of scope items to confirm: demolition, haul-off, utilities, irrigation sleeve/wire, soil import, protection of existing trees, allowances, and exclusions. Price each checklist line or explicitly exclude it.
Selects and specifies plants without first establishing soil texture, pH, infiltration/drainage, and slope, then applies one generic planting detail and amendment rate to every site.
Candidates treat soils as background information rather than design input, and amendment 'rules of thumb' are easy to recall and hard to apply selectively; clay versus sandy behavior is invisible in a photo or a written scenario unless you look for it.
What to do instead
Before specifying anything, run the sequence: observe slope and drainage patterns and high-water marks, read a soil test (texture, pH, salinity, infiltration), then set amendment and drainage design to the result - and check that drainage discharges legally on site rather than to a neighbor or storm drain.
Chooses plants by appearance alone - placing a shrub with a 15- to 20-foot mature spread in a 4-foot foundation bed, or putting high-water-use plants on the same hydrozone and valve as low-water natives.
The exam and the field both present attractive plants first; mature size, root behavior, sun/shade, water-use category, and fire or utility clearance are lookup facts that candidates skip because they believe they already know the plant.
What to do instead
For every plant on a list, state mature height and spread, water-use category, sun exposure, and any clearance issue (foundation, walkway, overhead lines, fire-defensible space) before scoring it as suitable. Group selections by hydrozone so plant list and irrigation zones are built together.
Mixes head types with different precipitation rates on a single valve, or sizes laterals and valves without a pressure budget (static pressure minus meter, elevation, backflow, and friction losses).
Zoning by 'area of the yard' is intuitive and zoning by precipitation rate and plant water need is not; candidates also forget that drip (GPH) and spray (in/hr) cannot be scheduled on one station, and skip friction loss because it is a multi-step calculation.
What to do instead
Zone by matched precipitation rate and plant water need, never by convenience. Do the pressure budget before choosing nozzles: static pressure, subtract meter and backflow losses, subtract 0.433 psi per foot of elevation, subtract friction loss for the actual flow and pipe size, and confirm the remaining pressure meets the head's operating range.
Carries a pedestrian/patio base detail into a vehicle area - specifying a thin single-lift aggregate base for a driveway or dropping pavers on native soil without compacted subgrade, geotextile, or edge restraint.
One familiar detail gets reused on every hardscape question, and base depth is buried in a detail drawing that candidates skim; traffic loading and subgrade condition are not obvious from the plan view.
What to do instead
Match the section to the loading: identify pedestrian versus vehicle traffic and the subgrade type first, then set compacted base depth, compaction in lifts, geotextile where subgrade is fine-grained or wet, edge restraint, and positive surface slope for drainage. Always state the drainage path off the pavement.
Plants trees and shrubs with the root flare buried below grade, leaves synthetic burlap, twine, or wire baskets in place, or skips the water-in and saucer that establishment depends on.
Nursery stock arrives with the flare obscured by soil and wrap, so 'plant it at the same depth it came in' feels correct; candidates also confuse staking and wrapping as always-required steps rather than case-by-case.
What to do instead
Set the root flare at or slightly above finished grade, remove all wrap and tie material from the trunk and flare area, backfill in lifts and water in to settle, form a saucer, and apply mulch without touching the trunk. Justify staking only when the root ball cannot hold the tree.
Prunes on a calendar habit rather than the plant's bloom cycle and growth habit - shearing spring-flowering shrubs in winter, topping trees, or removing more than about a quarter of the canopy in one season.
Maintenance schedules are driven by crew availability, and 'tidy it up' shearing is fast and looks finished; the flower buds and renewal wood being removed are not visible on a clipped hedge, so the error is not self-correcting.
What to do instead
Classify each plant before cutting: shrubs that bloom on last year's wood are pruned right after bloom, those on current-season wood in late winter/early spring. Use renewal and thinning cuts rather than topping, and keep any single-season removal to roughly 25 percent of the canopy.
Treats every symptom as a pest or disease and reaches for a pesticide - spraying for insects on damage caused by overwatering, compaction, or herbicide drift, or applying a pre-emergent to weeds that have already emerged and to the wrong timing window.
Visible damage demands a visible action, and abiotic disorders mimic disease; label rates, growth stage, soil temperature, and incorporation/irrigation requirements for pre-emergents are easy to skip under time pressure.
What to do instead
Run an IPM diagnosis first: map the symptom distribution (uniform over an area suggests abiotic; scattered and spreading suggests biotic), check irrigation and soil conditions, and identify the organism before selecting any product. Then read the label for site, rate, growth stage, temperature, and watering-in requirements before applying.
Answers jobsite and business-compliance questions from general instinct rather than the specific rule - excavating before the utility locate ticket expires or shoring a trench only by feel, and quoting deposit terms or contract language that exceed the statutory limits.
Safety and licensing rules are memorized as vague principles ('call before you dig', 'get a deposit'), while the exam tests the numbers and procedures; the field habit of starting work when the crew is available overrides the waiting period.
What to do instead
Memorize the operating numbers as a short list: utility locate request timing before excavation and hand-dig tolerance near marked lines, protective system required once a trench reaches 5 feet, and home improvement contract limits (down payment capped at 10 percent or $1,000, whichever is less) plus the cancellation notice requirement. Treat these as fixed facts, not judgment calls.