OR Landscape Contractor cheat sheet

ORS 671.505–671.695 is the Landscape Contracting statute; the Landscape Contractors Board's administrative rules sit in OAR chapter 808.

Landscape contracting means planning, designing, installing, constructing, planting, or maintaining landscape and its appurtenances for another person for compensation.

A standard license authorizes the full scope of landscape contracting; a limited license restricts the business to the specific specialty activities named on the license.

Licensure is issued to the business, and the business must maintain a qualified responsible individual who has passed the LCB examination.

A surety bond and liability insurance must be maintained continuously as a condition of licensure; a lapse is grounds for suspension.

The LCB may investigate complaints and impose civil penalties, suspend or revoke a license, or require mediation or arbitration of consumer disputes.

Abandoning a contracted job without justification is a violation of ORS 671 independent of any civil breach-of-contract claim.

Applying pesticides for hire requires an Oregon Department of Agriculture applicator license in addition to the LCB business license.

License renewal requires completion of LCB-approved continuing education within each renewal cycle; failure to complete it blocks renewal.

Match plant to site using USDA hardiness zone (Oregon spans roughly zones 4–9 by region and elevation), light exposure, mature height and spread, water use, and soil drainage.

Dig the planting hole 2–3 times the root-ball diameter and only as deep as the root ball, so the root flare sits at or about 1 inch above finished grade.

On balled-and-burlapped stock remove twine, burlap, and the wire basket from at least the top half of the ball; on container stock score or cut circling roots.

Backfill with the excavated soil and amend the entire planting bed rather than the backfill, avoiding a sharp textural interface between hole and native soil.

Apply 2–4 inches of organic mulch over the root zone, keeping mulch 1–2 inches clear of the trunk or crown.

In western Oregon, October–November planting lets roots establish before summer drought; cold, high-elevation sites favor spring planting.

Identify woody plants by leaf arrangement (alternate, opposite, whorled), leaf type (simple vs. compound), margin, buds, bark, and fruit.

Do not specify Oregon-listed noxious weeds or aggressive invaders such as English ivy, Himalayan blackberry, and Japanese knotweed.

Water new stock at planting to settle soil, then irrigate deeply and infrequently through the first two growing seasons.

Precipitation rate in inches per hour = (96.25 × zone gallons per minute) ÷ irrigated area in square feet.

Keep only matched-precipitation heads on a zone; mixing head types with different output lowers distribution uniformity.

Design velocity in PVC laterals at or below 5 feet per second (3–4 ft/s preferred) to limit friction loss and water hammer; use thrust blocks at direction changes.

Typical operating pressures: spray heads about 30 psi, rotors 45–50 psi, drip 20–30 psi; add pressure regulation when static pressure exceeds design.

Backflow protection is required at the potable connection: an RPZ for high hazard and a PVB or DCVA for low hazard, tested annually by a certified tester.

Zones should follow hydrozones (sun vs. shade, plant type, soil, slope), not just the geometry of the property.

Drip emitters typically run 0.5–2.0 gallons per hour; use pressure-compensating emitters on slopes and long runs.

Use cycle-and-soak scheduling on clay soils, plus a rain sensor and seasonal adjustment, to prevent runoff and overwatering.

Winterize with compressed air only within pipe pressure ratings (commonly no more than 50 psi at the compressor), blowing one zone at a time.

Gross margin % = (revenue − direct job costs) ÷ revenue; markup % = margin ÷ (1 − margin), so a 25% margin equals a 33.3% markup.

Break-even revenue = total annual fixed overhead ÷ gross margin percentage.

Labor burden = base wage plus payroll taxes, workers' compensation, benefits, and paid leave; typically 25–40% added to the hourly wage.

Current ratio = current assets ÷ current liabilities; a ratio below 1.0 signals cash-flow risk.

Oregon requires workers' compensation coverage for employees; a sole proprietor with no employees is not required to carry it for themselves.

Fully absorbed overhead rate = annual overhead ÷ annual direct labor or revenue dollars; it is applied to every estimate.

Bill progressively with deposits and progress payments so cash collected stays ahead of cash spent on payroll and materials.

Retainage on Oregon construction contracts is commonly 5% and is released at substantial completion or after the statutory period.

Estimate sequence: quantity takeoff → material and equipment costs → labor hours × burdened rate → subcontractor quotes → overhead and profit.

Apply material-specific waste factors (about 5–10% for pavers, 10% for sod, 5% for pipe) plus a contingency for unknowns.

Bid price = total direct cost ÷ (1 − overhead % − profit %); dividing by the complement is required because overhead and profit are percentages of price, not cost.

A written contract should state parties, scope and specifications, price and payment schedule, start and completion dates, change-order procedure, warranty, and dispute resolution.

Change orders must be written, priced, and signed before the changed work proceeds.

Oregon's home solicitation rules give a buyer three business days to cancel a contract signed at the buyer's home.

Oregon construction liens must be recorded within 75 days after completion of the improvement to preserve lien rights.

Read the instructions to bidders, general and special conditions, and every addendum, and acknowledge addenda on the bid form.

Unit-price items are paid on measured quantities; lump-sum items are paid on completion milestones.

Soil texture is named from sand, silt, and clay percentages on the textural triangle; loam is near 40% sand, 40% silt, and 20% clay.

A productive soil volume is roughly 50% solids, 25% water, and 25% air; compaction raises bulk density and squeezes out the air-filled pore space.

Never till or drive equipment on soil when it is wet - it destroys structure and creates a hardpan layer.

Till 2–4 inches of compost into the top 6–8 inches of a planting bed, and base pH and nutrient amendments on a soil test.

Most landscape plants prefer pH 6.0–7.0; western Oregon soils are commonly acidic (pH 5.0–6.0) and eastern Oregon soils alkaline.

Provide at least 2% surface slope away from structures; 3:1 is the steepest practical mowable slope, with 4:1 preferred.

French drain: perforated pipe in washed drain rock, filter fabric separating rock from soil, and a minimum 1% fall to a daylighted outlet.

Strip and stockpile topsoil separately from subsoil during cut-and-fill, and balance cut and fill to reduce haul-off.

Oregon DEQ's 1200-C construction stormwater permit applies to ground disturbance of 1 acre or more; use silt fence and wattles for perimeter control.

Paver base: 4 inches of compacted aggregate for pedestrian loads, 6–8 inches for vehicle loads, 1 inch of bedding sand, with base compacted to 95% standard Proctor.

Slope paving 1–2% (about 1/8 inch per foot, roughly 1%) away from buildings; ponding indicates inadequate slope or settlement.

Install edge restraint on every paver perimeter and fill joints with polymeric or stabilized joint sand.

Concrete walks are typically 4 inches thick, driveways 5–6 inches, at about 4,000 psi; control joints at 8–10 feet and isolation joints at fixed objects.

Segmental retaining walls bury the first course, batter about 1 inch per foot of height, and use free-draining gravel backfill wrapped in filter fabric with a base drain.

Walls with more than 4 feet of exposed height, or with surcharge loads, require engineered design and permits under the Oregon Residential Specialty Code.

Steps: 6–7 inch risers and 12–14 inch treads, keeping 2R + T between about 24 and 27 inches, with uniform risers throughout.

Compact subgrade and base in 2–4 inch lifts with a plate compactor, and verify compaction before setting units.

Provide weep holes and subsurface drainage behind walls and beneath pavers to relieve hydrostatic pressure and limit frost heave.

Mow no more than one-third of the blade height per mowing; cool-season lawn height is 2.5–3.5 inches, and 3–4 inches in shade.

Nitrogen: about 1 lb N per 1,000 square feet per application, 3–4 lb N per 1,000 square feet per year for cool-season turf.

Irrigate deeply and infrequently, about 1–1.5 inches per week including rainfall, to encourage deep rooting.

Thatch over about one-half inch calls for core aerification or dethatching; fall (September–October) is the prime renovation window in western Oregon.

Overseeding rates: tall fescue or perennial ryegrass 6–8 lb per 1,000 square feet; Kentucky bluegrass 2–3 lb per 1,000 square feet.

Remove no more than about 25% of a tree's live canopy in one year, and make pruning cuts at the branch collar without leaving stubs.

Keep mower blades sharp; dull blades shred leaf tips, producing gray-white tips and entry points for disease.

Base fertilizer, lime, and sulfur rates on a soil test rather than on visual guesswork.

Maintain 2–4 inches of mulch in beds and keep it off trunks and crowns to prevent rot and rodent damage.

IPM sequence: identify the pest → monitor and scout → compare to threshold → combine cultural, biological, mechanical, and chemical tactics → evaluate results.

The pesticide label is legally binding: site, target pest, rate, timing, PPE, restricted-entry interval, and preharvest interval must all be followed.

REI is the restricted-entry interval after application; PHI is the preharvest interval before harvest - both are printed on the label.

Rotate mode-of-action groups (IRAC, FRAC, WSSA codes) to delay pesticide resistance.

Oregon pesticide applicator licensing is administered by the Oregon Department of Agriculture; applying pesticides for hire requires the appropriate category license.

Oregon restricts the four neonicotinoids imidacloprid, clothianidin, thiamethoxam, and dinotefuran on linden and basswood trees because of bee kills.

Protect pollinators by not spraying open blossoms, applying when bees are not foraging, and following label pollinator warnings.

The Worker Protection Standard requires training, decontamination supplies, and application notification for workers on agricultural establishments such as nurseries.

Record every application: date, time, location, product name, EPA registration number, rate, target pest, and applicator.

Oregon OSHA administers workplace safety rules in OAR 437, and ORS 654.010 requires employers to furnish a safe workplace.

Call 811 (Oregon Utility Notification Center) at least two business days before any excavation and wait for locate marks before digging.

Excavations 5 feet or deeper require a protective system, and a ladder must be within 25 feet of workers in the trench.

Keep spoil piles, materials, and equipment at least 2 feet back from the excavation edge.

Maximum slope allowances: Type A soil 3/4:1, Type B 1:1, Type C 1½:1; a registered professional engineer is needed for alternatives.

Fall protection is required at 6 feet in construction - guardrail systems, personal fall arrest, or ladder systems.

Hearing protection and a hearing conservation program are required at 85 dBA time-weighted average over 8 hours; use double protection above 100 dBA.

Chainsaw PPE: chaps, face shield or safety glasses, hearing protection, and cut-resistant gloves; never cut above shoulder height.

Heat illness prevention: water, rest, shade, gradual acclimatization, and a buddy system; confusion or cramping means remove the worker from the heat.

The LCB licenses businesses rather than individuals, and each licensed business must keep a qualified responsible individual on record.

License status, bond, and insurance can be verified through the LCB's public license lookup before entering a contract.

Consumer complaints may proceed to the LCB's mediation or arbitration process in addition to any court action.

Oregon's home solicitation rules give a buyer three business days to cancel a contract signed at the buyer's home.

Check hardiness zone, light, mature size, and soil moisture before purchase; a mismatched plant fails regardless of planting quality.

Plant the root flare at or slightly above grade and never bury the trunk.

Amend the whole bed, not just the backfill, to avoid a perched water table at the hole interface.

Mulch 2–4 inches deep, kept clear of the trunk, and water newly installed stock to settle the soil.

Precipitation rate = 96.25 × GPM ÷ square feet, giving inches per hour for the zone.

Keep matched precipitation heads on a zone and design lateral velocity at or below 5 feet per second.

Provide RPZ, PVB, or DCVA backflow protection at the potable connection and test the assembly annually.

Schedule by hydrozone with rain sensors, seasonal adjustment, and cycle-and-soak on clay soils.

Margin and markup are not the same; convert with markup = margin ÷ (1 − margin).

Break-even revenue = fixed overhead ÷ gross margin percentage.

Labor burden of 25–40% above base wage must be included in every labor rate.

Bill progressively so collections stay ahead of payroll and material spending.

Bid price = direct cost ÷ (1 − overhead % − profit %) rather than direct cost plus percentages.

Written change orders signed before work proceeds protect both price and schedule.

Oregon construction liens must be recorded within 75 days after completion of the improvement.

Read and acknowledge every addendum when submitting a bid.

Texture comes from the sand-silt-clay triangle; structure and pore space are destroyed by working soil wet.

Provide at least 2% slope away from structures; keep mowable slopes at 3:1 or flatter.

French drains need washed rock, filter fabric, and at least 1% fall to an outlet.

Ground disturbance of 1 acre or more requires an Oregon DEQ 1200-C permit.

Compacted base is 4 inches for walks and 6–8 inches for drives, with 1 inch of bedding sand.

Slope paving 1–2% away from buildings and install edge restraint on all perimeters.

Retaining walls batter about 1 inch per foot and drain through gravel backfill, filter fabric, and a base drain.

Exposed wall height over 4 feet requires engineered design and permits.

Follow the one-third rule when mowing and keep cool-season turf at 2.5–3.5 inches.

Apply about 1 lb N per 1,000 square feet per application, 3–4 lb per year on cool-season lawns.

Aerate or dethatch when thatch exceeds one-half inch, preferably in early fall.

Base fertilizer and pH correction on a soil test.

Treat only when monitoring shows the pest has reached the action threshold.

The label governs site, rate, PPE, REI, and PHI, and is legally enforceable.

Rotate IRAC, FRAC, and WSSA mode-of-action groups to slow resistance.

Oregon applicator licensing runs through the Oregon Department of Agriculture, and application records are required.

Call 811 at least two business days before digging and wait for locates.

Trenches 5 feet or deeper need a protective system, with a ladder within 25 feet.

Fall protection is required at 6 feet in construction work.

Hearing protection is required at 85 dBA TWA over eight hours.