MN Landscape cheat sheet

Slope formula: percent grade = (rise ÷ run) × 100; a 2% minimum surface slope is standard for positive drainage away from structures.

Paver base depth rule of thumb: 4 in compacted aggregate for pedestrian patios, 6 in for residential driveways, 8–12 in for vehicle loads over poor subgrade.

Retaining wall rule: walls above 4 ft (1.2 m) measured from footing generally require engineered design, permitting, and geogrid reinforcement.

Segmental wall batter is typically 1 in per 12 in of height; geogrid layers are spaced no more than every other course in the reinforced zone.

Soil volume for trees: a common specification is 2 cubic feet of loamy soil per 1 square foot of canopy projection, or roughly 1,000 cu ft per large shade tree.

Plant spacing: set transplants so root balls are spaced at the mature spread radius, not the nursery container width; overplanting drives long-term removal costs.

Frost depth governs footing depth for freestanding walls, pergolas, and light posts; footings must bear below the local frost line.

Hardscape excavation subgrade should be proof-rolled and compacted to 95% Standard Proctor before aggregate base placement.

Drainage: a 1-in-per-10-ft swale moves water at low velocity; use 2% or steeper for turf swales to avoid ponding.

Mowing height rule: remove no more than one-third of the leaf blade per cut; cool-season turf is typically maintained at 2.5–3.5 in, warm-season at 1–2 in.

Fertilizer label math: lbs of nutrient = (lbs of product) × (%N or P2O5 or K2O ÷ 100); a 50-lb bag of 10-10-10 delivers 5 lb each of N, P, and K.

Soil pH targets: most turfgrasses 6.0–7.0; acid-loving plants such as rhododendron and blueberry 4.5–5.5.

Pre-emergent timing is driven by soil temperature: crabgrass germinates near 55°F at 1 in depth, so applications are timed to that threshold.

IPM scouting thresholds: treat only when monitoring shows pest populations above the action threshold; record counts, dates, and beneficials.

Pruning timing: spring-flowering shrubs are pruned right after bloom; summer-flowering shrubs are pruned in late winter or early spring.

Mulch depth: 2–3 in over root zones, kept 1–2 in away from trunks to prevent crown rot and rodent damage.

Compost maturity indicators: stable temperature, earthy odor, and a respiration test below the target rate; immature compost can tie up nitrogen.

Snow and ice: rock salt (NaCl) damages turf and concrete; calcium magnesium acetate or sand is preferred near plantings and new hardscape.

Container media: a soilless mix of peat or bark, perlite, and vermiculite provides drainage and air porosity; field soil is not used in containers.

Fertilizer rate for containers: constant liquid feed at 100–200 ppm N is typical for greenhouse crops, adjusted by crop and stage.

pH in soilless media: target 5.5–6.2 for most greenhouse crops; pH above 6.5 induces iron and manganese deficiency.

DIF (day minus night temperature) controls stem elongation: a negative DIF (cooler days than nights) shortens internodes without growth regulators.

Winter hardiness: USDA zones map average annual minimum temperature; a plant's zone rating is a guide, not a guarantee, and microclimate matters.

Vernalization: biennials and some perennials require a cold period (typically 6–10 weeks near 40°F) to flower.

Photoperiod: short-day plants flower when night exceeds a critical length; long-day plants flower when night is shorter than the critical length.

Irrigation water alkalinity above about 150 ppm CaCO3 raises media pH over time; acid injection or acid-loving fertilizer corrects it.

Inventory quality: root circling in containers signals the need to up-pot or root-prune; circling roots reduce transplant survival.

Precipitation rate formula: PR (in/hr) = 96.3 × GPM ÷ (head spacing in ft × row spacing in ft) for square spacing.

Application rate must not exceed soil infiltration rate; if it does, use cycle-and-soak or split run times.

Distribution uniformity (DU) is measured by catch-can tests; low quarter DU below about 70% indicates nozzle, pressure, or spacing problems.

Pressure: most spray heads are rated near 30 psi and rotors near 45–50 psi; excess pressure causes misting and wind drift losses.

Scheduling: replace the controller's seasonal adjust with evapotranspiration (ET) data; ET-based scheduling reduces water use versus fixed run times.

Backflow prevention is required on all irrigation connections to potable supply; the type (RPZ, PVB, DCVA) depends on local code and hazard level.

Drip systems are rated in GPH per emitter and operate at lower pressure (typically 10–25 psi) with higher uniformity than spray.

Winterization: blow-out with air should not exceed the manufacturer's pressure rating, commonly 50 psi at the compressor, and zones are run one at a time.

Water budget: gallons = area (sq ft) × depth (in) × 0.623; a 1,000 sq ft lawn receiving 1 in uses about 623 gallons.

Pruning cut rule: make the final cut just outside the branch bark ridge and collar, not flush with the trunk.

The 3-cut method prevents bark tearing on heavy limbs: undercut, top cut outside the undercut, then final cut at the collar.

ANSI A300 is the standard for tree care operations; Z133 covers safety requirements for arboricultural operations.

Tree risk assessment: use a matrix of likelihood of failure and consequences of failure; assign mitigation based on the combined rating.

Root protection zone: a common specification is 1 ft of radius per 1 in of trunk diameter, with no grade change or compaction inside it.

Topping is prohibited practice; it creates decay, weak sprout attachments, and long-term hazard.

Cabling and bracing are installed only after an arborist assessment; they support, but do not repair, structural defects.

Stump grinding depth: grind 6–12 in below grade; deeper grinding is needed where replanting will occur in the same location.

Tree injection and fertilization: apply when soil tests show deficiency; nitrogen is typically applied at 1–4 lb per 1,000 sq ft of root zone.

Note: this section is intentionally omitted; the six required domains are covered in the five sections above plus the cross-references below.

Controller programming: set start times, run times, and days; use multiple start times for cycle-and-soak on clay soils.

Rain sensors and soil moisture sensors interrupt scheduled irrigation; check them seasonally for function and setting.

Leak diagnosis: static pressure test and flow test isolate mainline leaks from lateral or valve leaks.

Valve troubleshooting: a valve that will not close usually has debris at the diaphragm or a failed solenoid; a valve that will not open usually has a wiring or solenoid fault.

Nozzle matching: do not mix spray and rotor heads on one zone; matched precipitation rate keeps uniform application.

Water source: reclaimed water requires purple pipe and backflow protection appropriate to the hazard class.

Meter sizing: peak demand is the sum of zone flow rates; size the meter and mainline for peak, not average, demand.