AL Landscape common mistakes
AL Landscape · Understand the traps and how to avoid them.
Treating slope as rise/run in the wrong units-computing a 2% grade by dividing a 1 ft rise by 50 ft run but reporting it as 0.02 inches per foot, or mixing feet and inches in the same calculation and accepting the resulting number.
Candidates learn the formula 'rise over run times 100' but practice with clean metric or whole-foot examples, so unit conversion under exam pressure breaks down; inches-to-feet conversion (divide by 12) is the usual failure point.
What to do instead
Before computing, write every dimension in a single unit (convert all inches to decimal feet). Compute grade as (rise in ft / run in ft) x 100 and sanity-check: a 2% slope over 50 ft must be 1 ft, not 12 in mislabeled as feet. Practice 10 mixed-unit conversions until they are automatic.
Drawing or interpreting contour lines as if water flows along them, or placing swales and drainage inlets on the contour rather than perpendicular to it.
Contour lines look like flow paths on a plan, and candidates who learned 'water follows the line' from a stream analogy misapply it; the concept that water crosses contours at right angles is abstract without field experience.
What to do instead
Anchor the rule with a physical model: water flows perpendicular to contours, downhill. On any plan, draw flow arrows crossing each contour at 90 degrees before locating inlets, swales, or berms, and verify each arrow points from higher to lower elevation.
Selecting plants by mature height only, ignoring mature spread, root-space needs, and hardiness-zone or exposure mismatch, so the specified plant is 'correct' on paper but wrong for the site.
Height is the most visible number on a plant tag, and candidates under time pressure grab the first species that fits the vertical dimension without cross-checking spread against the planting bed width or the site's zone.
What to do instead
Use a fixed checklist for every plant-selection item: hardiness zone, light exposure, mature height AND spread, soil moisture, and root/clearance conflicts. Reject any option that fails even one criterion before comparing aesthetics.
Confusing the sequence of construction operations-specifying finish grading before rough grading and utility trenching, or ordering paving base before subgrade compaction-when answering sequencing questions.
Candidates memorize individual steps but not the dependency chain, and exam distractors list plausible steps in a shuffled order that sounds logical in isolation.
What to do instead
Memorize the canonical chain: clear and grub, rough grade, utilities and drainage, subgrade prep and compaction, base course, finish grade, then planting and surfacing. For any sequencing item, ask 'what must be finished before this step can start?' and eliminate out-of-order options.
Sizing irrigation zones and pipe by counting heads only, without converting to flow in gallons per minute and checking against available pressure and pipe velocity limits.
Head counts are easy to tally; flow and pressure math requires multiplying head GPM by count and comparing to supply, which candidates skip under time pressure or because they never practiced the full calculation.
What to do instead
For every irrigation item, compute total zone demand (heads x GPM per head), compare to available flow at the point of connection, and check that pipe size keeps velocity in range. If the numbers are not given, state the assumption explicitly rather than guessing.
Answering maintenance questions with a single blanket schedule ('water daily', 'prune in spring') instead of matching the practice to species, season, soil moisture, and establishment stage.
Candidates default to general gardening advice they already know rather than the exam's site-specific logic, and distractors reward the familiar-sounding generalization.
What to do instead
For each maintenance item, identify the plant's establishment phase and the season referenced in the stem. Established plants need deep infrequent irrigation; new plantings need more frequent monitoring. Choose the option that names the specific condition, not the universal rule.
Treating 'sustainable' as a synonym for 'native only' or 'no irrigation', rejecting correct answers that include adapted non-native species, hydrozoning, or efficient irrigation.
Marketing language around sustainability is oversimplified, and candidates apply an ideological filter instead of the technical criteria (water use, soil health, biodiversity, lifecycle impact) the exam tests.
What to do instead
Judge each option against measurable criteria: does it reduce potable water demand, improve soil or stormwater performance, or support habitat? Select the option with the strongest technical justification even if it is not the most 'purist' choice.
Computing a bid by summing material and labor costs and stopping there, omitting overhead, profit, contingency, and sales tax, or applying markup to the wrong base.
Candidates conflate markup and margin and forget that overhead and profit sit on top of direct cost; the arithmetic feels complete once direct costs are totaled.
What to do instead
Use a fixed bid ladder: direct cost, then add overhead percentage, then profit percentage, then tax where applicable. Distinguish markup (percent of cost) from margin (percent of price) explicitly, and practice converting between them until the difference is obvious.
Reading a project-management question as a technical question-proposing a design fix when the stem asks about contract scope, change orders, or client communication.
Candidates are trained in design and construction and reflexively solve the physical problem, missing that the correct answer addresses the contractual or communication process.
What to do instead
Classify each stem before answering: is it asking what to build, or how to manage the decision? For management items, prefer the answer that documents the change, confirms scope in writing, and follows the contract sequence over the one that is technically clever.
Ignoring the site's existing conditions and microclimate when laying out a design-placing a shade-loving bed on a south-facing wall or a patio in the path of prevailing winter wind-because the plan looks balanced on paper.
Candidates evaluate layouts visually and symmetrically rather than testing them against sun angles, wind direction, drainage, and existing vegetation described in the stem.
What to do instead
Before choosing a layout, extract every site fact from the stem (orientation, prevailing wind, existing trees, slope, views) and list them. Eliminate any option that contradicts a stated site fact, then compare the survivors on function.