CA Landscape flashcards

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

Plan scale 1"=10'

A drawing scale where one measured inch on the plan equals 10 feet on the ground, so a 3-inch plan distance represents 30 field feet.

Contour interval

The constant vertical distance in elevation between two adjacent contour lines on a grading or topographic plan, stated in the sheet legend.

Spot elevation

A point elevation printed on a plan to hundredths of a foot, marking a specific grade such as a building corner, inlet, or high point.

Cubic yard formula

Volume in cubic yards equals length in feet times width in feet times depth in feet, divided by 27, the number of cubic feet in a cubic yard.

Triangular spacing plant count

The number of plants needed in staggered rows equals the planted area divided by the square of the spacing multiplied by 0.866.

Waste factor

A percentage added to a quantity takeoff to cover cuts, breakage, and overfill, typically 5 to 10 percent for hard goods and 10 to 15 percent for plants and sod.

Soil ribbon test

A field texture test in which moist soil is squeezed into a ribbon; under one inch suggests sandy loam, one to two inches loam, over two inches clay.

Percent slope formula

Slope in percent equals rise divided by run, multiplied by 100; a 1-foot drop over a 20-foot distance is a 5 percent slope.

French drain

A subsurface drain built from washed aggregate, filter fabric, and perforated pipe laid at about 1 percent slope to carry groundwater to daylight or a sump.

USDA hardiness zone

A geographic rating based on the average annual minimum temperature; zone 7, for example, corresponds to winter lows of roughly 0 to 10 degrees Fahrenheit.

Hydrozoning

Grouping plants with similar water requirements onto the same irrigation valve so that each zone can be scheduled to match its actual water demand.

Full sun definition

A site condition receiving six or more hours of direct sunlight daily; part shade means three to six hours or filtered light, and shade is under three hours.

Precipitation rate formula

Sprinkler application rate in inches per hour equals 96.3 times the flow per sprinkler in gallons per minute divided by head spacing times row spacing in feet.

Head-to-head spacing

Placing sprinklers so each throws water to the next head, typically 50 to 60 percent of the published throw diameter, which produces the most uniform coverage.

PVB backflow preventer

A pressure vacuum breaker stops potable supply contamination by irrigation backflow and must be installed at least 12 inches above the highest downstream head.

Cycle and soak

A controller schedule that splits a zone's runtime into several short cycles with soak pauses so water infiltrates rather than running off sloped or clay soils.

Aggregate base compaction

Base stone is placed in lifts of 2 to 4 inches and compacted to about 95 percent density, using 4 inches for walks and 6 to 8 inches for driveways.

Control joint spacing

Sawed or formed joints in concrete flatwork that create planned cracking planes, typically spaced every 8 to 12 feet in landscape walks and patios.

Retaining wall batter

A slight backward lean of about 1 inch per foot of wall height that improves stability and appearance of a segmental or masonry retaining wall.

Planting hole width rule

The planting hole should be two to three times the width of the root ball but no deeper, so the root flare sits at or slightly above grade.

Root flare

The point where the trunk widens into the major roots; it must be visible at or just above the finished soil grade after planting to prevent girdling and decline.

Mulch ring depth

An organic mulch layer 2 to 4 inches deep spread over the root zone, pulled back 2 to 3 inches from the trunk to prevent rot and rodent damage.

One-third mowing rule

Never remove more than one-third of the total grass blade height in a single mowing, because removing more stresses turf and thins the stand.

Branch collar cut

The final pruning cut is made just outside the swollen branch collar, not flush with the trunk, so the tree can seal the wound efficiently.

Dethatching

Mechanical removal of the dead stem and root layer between soil and green grass, performed when thatch exceeds about one-half inch and before overseeding.

Disease triangle

Plant disease requires a susceptible host, a virulent pathogen, and favorable environmental conditions at the same time; removing any one factor stops the disease.

Preemergence herbicide

A herbicide applied to soil before weed seeds germinate, forming a barrier that kills emerging seedlings; crabgrass timing is keyed to soil near 55 degrees Fahrenheit.

Action threshold

The pest population or damage level at which treatment is justified, balancing control cost and risk against the damage the pest would cause.

811 one-call notification

The free service that marks underground utilities before excavation; contractors must call and wait the required notice period before digging.

Trench protective system

Shoring, shielding, or sloping required for trenches five feet deep or more, with a ladder within 25 feet for worker exit at four feet.

Silica dust control

Wet cutting or water-fed tools with a respirator when cutting concrete, masonry, or stone to limit worker exposure to respirable crystalline silica.

Hearing protection threshold

Hearing protection must be provided and worn at an eight-hour time-weighted average exposure of 85 decibels, a level exceeded by chainsaws and blowers.