Plain definitions of 35 terms we use on the job in Issaquah.
Term Index
Open any term below for a dedicated definition page.
A berm is a raised, shaped mound of soil used to guide water, create visual separation, protect plants, or add height to a landscape. Its slopes blend into the surrounding grade, so a berm looks like part of the land. Plants, mulch, stone, or lawn may cover its surface.
Also called: Landscape berm
Bioswale is a shallow, planted drainage channel that slows stormwater and helps water soak into the soil. A bioswale often uses gently sloped sides, amended soil, and water-tolerant plants. The channel can also trap soil and other pollutants before runoff reaches a drain, stream, or neighboring property.
Also called: Vegetated swale
A catch basin is a landscape drainage box with a grated cover, a sump, and an outlet pipe. Surface water enters through the grate, while soil and debris settle below the outlet. The pipe carries clearer water away from paved areas, planting beds, or low spots, helping direct runoff into a planned drainage system.
Also called: Drain basin
Composite decking is a manufactured deck-board material made from wood fibers, plastic, and binding agents. The boards are formed into consistent shapes and finished with a protective surface. Composite decking is used for walking surfaces, stairs, and other outdoor deck parts. It differs from natural wood because its color and texture are factory made.
Also called: Capped composite decking
A concrete sealer is a protective coating or treatment applied to cured concrete. It helps limit water entry, staining, dusting, and surface wear. Sealers may form a film on top or soak into the concrete. The right product depends on the concrete finish, exposure, appearance, and planned use.
Also called: Patio sealer
A control joint is a planned groove or separation in concrete that guides shrinkage cracking to a selected line. Concrete changes size as it dries and responds to temperature. The joint creates a weaker path, so cracks are more likely to form there instead of spreading across random areas of a patio.
Also called: Contraction joint
Deck Joist is a horizontal framing member that supports deck boards and transfers their load to beams, ledgers, or other supports. Joists run across the deck frame and create the surface structure beneath your walking area. Proper spacing, alignment, connections, and moisture protection help the deck stay stable and durable.
Also called: Joist
Deck Ledger is a horizontal board that attaches a deck to a building and supports the deck framing at that connection. The ledger transfers part of the deck load to the structure. Proper placement, fasteners, flashing, and drainage details help keep water from entering the wall behind the board.
Also called: Ledger board
A Deck Post is a vertical support that carries a deck’s framing and transfers its weight to a stable footing below. Posts help hold the deck level and support parts such as beams, joists, railings, and decking. Their size, spacing, and connection method depend on the deck design and site conditions.
Also called: Support post
Deck Railing is a barrier installed along the open edges of a raised deck, stair, or landing. It helps define the deck boundary and gives people a steady handhold as they move nearby. Deck railing may use wood, metal, composite, or glass components, depending on the deck design and site needs.
Also called: Deck guardrail
Drip Irrigation is a watering system that delivers water slowly through small emitters placed along tubing near plant roots. The system sends moisture directly to the soil around each plant, which helps limit overspray and runoff. Landscapers can adjust emitter placement for shrubs, perennials, vegetable beds, and other planted areas.
Also called: Dripline irrigation
Erosion Control is the practice of keeping soil in place and limiting its movement by rain, runoff, wind, or construction activity. The work may include shaping grades, slowing water, covering bare soil, and guiding runoff toward stable drainage areas. Proper control protects soil, plants, structures, and nearby waterways.
Also called: Soil erosion control
A footing is a widened base that supports a deck post, pier, wall, or other structure below ground. It spreads the structure’s weight across the soil and helps limit settling, shifting, and frost movement. Deck footings usually connect the ground support to posts that carry beams and joists above.
Also called: Foundation footing
Geotextile Fabric is a synthetic textile placed in soil to separate, filter, reinforce, or protect ground materials. In drainage work, the fabric lets water pass while limiting soil movement into gravel or pipe openings. The correct type depends on soil conditions, water flow, and the role the fabric must perform.
Also called: Filter fabric
Grading is the planned shaping of soil to create useful slopes and level areas on a landscape site. It directs rainwater away from buildings, patios, and walkways while supporting stable surfaces. Landscape designers use grading plans to show how the finished ground should rise, fall, and connect with nearby features.
Also called: Site grading
Hardscape is the built part of a landscape, including patios, walkways, retaining walls, steps, decks, and other fixed features. These elements use materials such as stone, concrete, brick, wood, or metal. Hardscape shapes movement, defines outdoor areas, supports drainage, and provides durable surfaces for daily use.
Also called: Hard landscaping
An irrigation controller is an electronic device that starts and stops watering zones on a set schedule. It sends signals to sprinkler or drip irrigation valves, which release water to selected areas. Many controllers adjust watering when paired with rain sensors, soil sensors, or weather-based settings. The controller does not supply water itself.
Also called: Sprinkler timer
Landscape Edging is a garden border that separates planting areas from lawns, paths, or other surfaces. It may use metal, stone, brick, plastic, wood, or living plants. Edging helps keep soil and mulch in place, defines bed shapes, and creates a clear line between different parts of a landscape.
Also called: Garden edging
Landscape Fabric is a permeable ground cover that blocks sunlight and slows weed growth while allowing water and air to pass through. Gardeners place it over prepared soil and secure it beneath mulch, gravel, or other surface materials. The material can also help separate soil from decorative stone in selected garden areas.
Also called: Weed-control fabric
Low-Voltage Lighting is an outdoor lighting system that runs on reduced electrical power through a transformer. The transformer changes household power to a lower level for landscape fixtures. This setup supports path lights, step lights, accent lights, and other fixtures used to guide movement or highlight outdoor features.
Also called: 12-volt landscape lighting
Mulch is a protective layer placed over soil around plants. It may contain wood chips, bark, leaves, compost, or other organic material. Mulch helps slow moisture loss, reduce weed growth, limit soil splash, and moderate soil temperature. As organic mulch breaks down, it also adds small amounts of organic matter.
Also called: Landscape mulch
Paver Base is a compacted layer of crushed stone placed beneath patio, walkway, or driveway pavers. It creates a firm foundation, helps spread weight, and supports drainage through the paving system. The base sits below the bedding layer and helps limit shifting, settling, and surface damage caused by moisture or repeated use.
Also called: Aggregate base
Permeable Pavers are paving units with joints or surfaces that let rainwater pass into a stone base below. The base stores and filters water before it moves into the soil. This design helps reduce surface runoff on patios, walkways, and driveways when the soil and drainage plan support infiltration.
Also called: Permeable concrete pavers
Pond Liner is a flexible waterproof membrane that holds water inside a pond or water feature. The liner separates water from surrounding soil and helps prevent seepage. Common materials include rubber and reinforced plastic. A pond liner must fit the pond shape and connect properly with drains, skimmers, and other pond equipment.
Also called: Water garden liner
A pond skimmer is a filtration box that removes floating leaves, pollen, and other debris from pond water. A floating weir draws surface water into the box as the pump pulls water through it. The skimmer protects the pump from larger debris and helps keep the pond surface cleaner.
Also called: Skimmer box
A Rain Barrel is a container that collects runoff from a roof or downspout for later landscape use. Stored water can help irrigate plants during dry periods, while an overflow connection directs extra water away from the container. Rain barrels work as part of a drainage plan, but they do not replace proper site grading.
Also called: Rainwater barrel
A rain sensor is an irrigation control device that detects rainfall and signals the sprinkler controller to pause watering. The sensor helps prevent irrigation during or after natural rain. It usually works with an automatic irrigation system and can be mounted outdoors where it receives open exposure to the weather.
Also called: Irrigation rain sensor
A root ball is the mass of roots and soil that supports a plant when the plant is moved or sold. The roots may be wrapped in burlap, held in a container, or exposed for bare-root planting. Keeping this mass intact helps protect fine roots during planting and supports early growth.
Also called: Tree root ball
Sod is pre-grown grass held together by a thin layer of soil and roots. Landscapers roll or lay sod across prepared ground to create an established lawn surface. Sod provides quick ground cover, helps reduce bare soil, and needs careful watering while its roots connect with the soil below.
Also called: Turfgrass
A soil amendment is a material mixed into existing soil to improve its structure, drainage, moisture holding, or nutrient supply. Common amendments include compost, aged manure, lime, and gypsum. The right choice depends on the soil’s texture, drainage, organic matter, and the needs of the plants in the planting design.
Also called: Soil conditioner
Soil Compaction is a condition where soil particles are pressed tightly together, reducing the open spaces that hold air and water. Compacted soil drains slowly, resists root growth, and may feel hard underfoot. Lawn installation teams check it before placing seed or sod because new grass needs loose soil for roots to spread.
Also called: Compacted soil
A swale is a shallow, sloped channel that guides and slows stormwater across a landscape. It may be covered with grass, planted with water-tolerant species, or finished with rock. Unlike a buried drain, a swale works at the surface, where soil and plants can help filter water before it leaves the site.
Also called: Drainage swale
A Trellis is a vertical or angled garden structure that supports climbing plants and adds height to a planting area. Trellises may stand alone or attach to a wall, fence, or raised bed. Common materials include wood, metal, and composite products. The open frame guides stems while allowing light and air through.
Also called: Plant trellis
An underdrain is a buried drainage system that collects excess water below the soil surface and carries it to a safe outlet. It usually includes perforated pipe, washed gravel, and filter fabric. Underdrains help control groundwater, protect planting areas, and reduce saturation beneath lawns, paths, walls, or other landscape features.
Also called: Subsurface drain
Weed Barrier is a material placed over prepared soil to block light and slow weed growth. Common types include landscape fabric, plastic sheeting, and paper products. The material sits beneath mulch, gravel, or other ground cover. It can reduce maintenance, but it doesn't replace good soil preparation or ongoing weed control.
Also called: Weed-blocking fabric
