CA Landscape key terms

The ratio printed on a drawing that converts a measured distance on paper into real-world distance, such as one inch equals twenty feet. Confirm the scale before measuring anything off a plan.

The systematic counting and measuring of every item shown on the drawings - square feet of paving, linear feet of pipe, number of plants - to produce the quantities an estimate is built from.

The cost of installing one measurable unit of work, such as a square foot of pavers or one fifteen-gallon tree, including labor, material, and equipment. Multiplying by takeoff quantities gives the bid total.

A written amendment to a signed contract that adjusts the scope, price, or schedule of the work. It should be documented and approved before the added or deleted work is performed.

The relative proportions of sand, silt, and clay particles in a soil. Texture governs how fast water drains, how much water is stored, and how easily roots and air move through the profile.

The speed at which water enters the soil surface, usually stated in inches per hour. It determines irrigation run times, drainage sizing, and whether a site will pond after storms.

The pressing out of air-filled pore space in soil by equipment, foot traffic, or grading. Compacted soil resists root growth and water movement, so it must be loosened or amended before planting.

A shallow, gently sloping channel that conveys or temporarily holds stormwater at the surface. A vegetated swale slows runoff and allows water to soak in rather than run off the site.

A climate rating based on average annual minimum temperature that predicts whether a plant can survive winter in a region. Local shelter, pavement, and elevation can shift the effective zone at a given spot.

The local conditions of light, heat, wind, and moisture at one specific spot, such as a hot south wall or a cool shaded courtyard, which differ from the surrounding regional climate.

The final list of species selected for a project, chosen to fit sun exposure, water supply, soil, mature size, and maintenance expectations. It is settled before layout and irrigation design are finalized.

The managed area around a building where vegetation is thinned, spaced, and maintained to slow the spread of wildfire, as required in California wildland-urban interface zones.

A portion of a landscape watered as a single unit because its plants share similar water needs. Grouping plants this way lets one valve deliver an appropriate schedule to the whole area.

The combined water lost from soil evaporation and plant transpiration, reported in inches per day or week. Controllers use reference ET with a plant factor to calculate how long to run each zone.

The speed at which sprinklers or emitters apply water to a zone, expressed in inches per hour. It is compared with plant water demand to set run times and avoid runoff.

A measure of how evenly an irrigation system applies water across a zone. Low uniformity means some plants are overwatered while others are starved, so schedules must be lengthened to compensate.

A device that stops irrigation water from reversing into the drinking water supply. Plumbing codes require one on each service, and most water agencies require annual testing.

The native or compacted soil beneath a paving installation, shaped and compacted before any base material goes down. Weak or uneven subgrade leads to settlement and cracked or rocking surfaces.

A compacted layer of graded crushed rock placed over subgrade to spread loads and drain water under paving. Its depth and gradation depend on the pavement type and expected traffic.

A high-strength polymer mesh laid in horizontal layers within a retaining wall or slope to reinforce the soil. It resists pullout and spreads loads, allowing taller walls with less mass.

A small opening left in a retaining or planter wall that lets trapped water escape. Without it, water pressure builds behind the wall and can push it over.

A joint sand containing a binder that hardens after wetting, locking pavers together and limiting weed growth and water penetration. It is swept into joints and activated per the manufacturer's directions.

The mass of soil and roots lifted with a plant when it is dug or slipped from its container. Keeping it intact and moist until planting is essential to survival.

The widened transition where a trunk meets its major roots. It must sit at or slightly above finished grade, because a buried flare rots and girdles the tree over time.

Field-grown stock dug with a firm ball of soil wrapped in burlap and held with twine or a wire basket. The ball must never be dropped or allowed to dry out.

The first one to three years after planting, when roots are growing into the surrounding soil and the plant still depends on supplemental water, weed control, and protection from damage.

A mat of dead stems, roots, and leaves lying between living turf and the soil surface. A thick layer sheds water, harbors pests, and blocks air, so it is removed by aeration or dethatching.

Pulling small plugs of soil out of turf to open the surface and relieve compaction. The holes let air, water, and fertilizer reach the root zone and encourage deeper rooting.

A pruning cut that removes a branch back to its point of origin or to a side branch, leaving no stub. It preserves the plant's natural form and lets light into the interior.

Removing spent flowers before seed forms. It redirects energy into new growth and further bloom, extends the flowering season, and keeps beds looking tidy.

A decision process that combines monitoring, treatment thresholds, cultural practices, biological controls, and pesticides used only when needed, starting with the least disruptive option.

The pest population level at which control is justified because the damage it will cause exceeds the cost of treatment. Scouting data determine when that level is reached.

A product applied to the soil surface before weed seeds sprout, forming a barrier that stops seedlings from establishing. It does nothing to weeds that are already growing.

The word on a pesticide label - DANGER, WARNING, or CAUTION - that ranks the product's acute toxicity and signals the level of protective equipment and handling care required.

A written workplace safety plan required of California employers, covering assigned responsibilities, hazard inspection, training, communication, and correction of unsafe conditions.

A standardized manufacturer document listing a product's hazards, safe handling, protective equipment, spill response, and first aid. Employers must keep sheets accessible to exposed workers.

The free notification service contacted before any digging so utility owners can mark buried lines. Crews must wait the required time and hand-dig near marked utilities.

Required practices for outdoor work in hot weather, including ready access to water and shade, rest breaks, acclimatization for new workers, and a plan for emergency response.

The site-specific document required under California's construction stormwater permit, describing erosion and sediment controls, material management, and inspection and reporting duties.