MN Landscape flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Percent grade

Percent grade equals rise divided by run, multiplied by 100. A 1-ft rise over 50-ft run is 2%, the minimum slope for drainage away from structures.

Paver base depth

Compacted aggregate base is typically 4 in for patios, 6 in for residential driveways, and 8–12 in for vehicle loads over weak subgrade.

Retaining wall threshold

Walls above 4 ft from the footing generally require engineered design, permits, and geogrid reinforcement. Batter is commonly 1 in per 12 in of height.

Tree soil volume

A common specification is 2 cubic feet of loamy soil per square foot of canopy projection, or about 1,000 cubic feet for a large shade tree.

Frost depth footing

Freestanding walls, pergolas, and light posts require footings that bear below the local frost line to prevent heaving and settlement.

One-third mowing rule

Remove no more than one-third of the leaf blade per cut. Cool-season turf is usually kept at 2.5–3.5 in; warm-season turf at 1–2 in.

Fertilizer nutrient math

Pounds of nutrient equals pounds of product times the label percentage divided by 100. A 50-lb bag of 10-10-10 supplies 5 lb each of N, P, and K.

Turf soil pH

Most turfgrasses perform best at pH 6.0–7.0. Acid-loving plants such as rhododendrons and blueberries prefer pH 4.5–5.5.

Crabgrass pre-emergent timing

Crabgrass germinates near 55°F soil temperature at 1 in depth. Pre-emergent applications are timed to that threshold, not to the calendar.

IPM action threshold

Treat only when monitoring shows pest populations above a set action threshold. Record counts, dates, and beneficial insect presence to justify treatment.

Pruning timing by bloom

Spring-flowering shrubs are pruned right after bloom because they set buds on old wood. Summer-flowering shrubs are pruned in late winter or early spring.

Mulch depth rule

Apply 2–3 in of mulch over the root zone, keeping it 1–2 in away from trunks to prevent crown rot, rodent damage, and secondary root growth.

Soilless container media

Container media use peat or bark with perlite and vermiculite for drainage and air porosity. Field soil is not used because it compacts and drains poorly.

Constant liquid feed rate

Greenhouse crops are commonly fertigated at 100–200 ppm nitrogen, adjusted by crop, stage, and leaching fraction. Higher rates risk salt injury.

Soilless media pH

Target pH 5.5–6.2 for most greenhouse crops. Above 6.5, iron and manganese become less available and interveinal chlorosis appears.

DIF stem elongation

DIF is day temperature minus night temperature. A negative DIF, with cooler days than nights, shortens internodes without chemical growth regulators.

USDA hardiness zone

Zones map average annual minimum temperature. The rating is a guide, not a guarantee; site microclimate, soil, and moisture also determine winter survival.

Vernalization requirement

Biennials and some perennials need a cold period, typically 6–10 weeks near 40°F, to initiate flowering. Without it, they remain vegetative.

Photoperiod response

Short-day plants flower when the night exceeds a critical length. Long-day plants flower when the night is shorter than the critical length.

Water alkalinity effect

Irrigation water above about 150 ppm CaCO3 raises media pH over time. Acid injection or acid-forming fertilizer corrects the drift.

Precipitation rate formula

PR in inches per hour equals 96.3 times GPM divided by head spacing times row spacing in feet, for square spacing patterns.

Cycle and soak

When application rate exceeds soil infiltration rate, split run time into cycles with soak intervals to prevent runoff and ponding.

Distribution uniformity

DU is measured by catch-can tests. Low-quarter DU below about 70% indicates nozzle wear, pressure problems, or improper head spacing.

Sprinkler pressure ratings

Spray heads are rated near 30 psi and rotors near 45–50 psi. Excess pressure causes misting, wind drift, and poor uniformity.

ET-based scheduling

Evapotranspiration-based controllers replace fixed run times with weather-driven schedules, typically reducing water use compared with seasonal adjust alone.

Backflow prevention

All irrigation connections to potable supply require backflow protection. The device type (RPZ, PVB, DCVA) depends on local code and hazard level.

Drip emitter ratings

Drip emitters are rated in gallons per hour and operate at 10–25 psi, delivering higher uniformity than spray heads and reducing wind losses.

Water volume formula

Gallons equal area in square feet times depth in inches times 0.623. A 1,000-sq-ft lawn receiving 1 in uses about 623 gallons.

Branch collar cut

Make the final pruning cut just outside the branch bark ridge and collar, not flush with the trunk, to preserve the tree's natural defense zone.

Three-cut method

For heavy limbs: undercut from below, make a top cut outside the undercut, then remove the stub with a final cut at the branch collar.

ANSI A300 and Z133

ANSI A300 sets tree care operation standards; Z133 covers safety requirements for arboricultural operations, including chainsaw and climbing rules.

Root protection zone

A common specification is 1 ft of radius per 1 in of trunk diameter. No grade change, trenching, or compaction should occur inside that zone.