Glossary

Landscape supply yards and lumber counters have their own vocabulary, and a good part of ordering well is knowing what to ask for. These are the terms that appear in our calculators and guides, along with the ones you are most likely to hear on the phone.

A to C

Actual size. The real, measured dimensions of a piece of lumber, as opposed to the nominal size it is sold under. A 2 × 4 is actually 1½ × 3½ inches.

Aggregate. A general word for crushed stone, gravel and sand used in construction, on its own or as an ingredient of concrete.

Amend. To improve soil by mixing something into it, usually compost or another organic material.

Analysis. The three numbers on a fertilizer bag, giving the percentages of nitrogen, phosphate and potash by weight. Also called the grade.

Backfill. Material placed behind a wall or around a post after it is set. Also the act of placing it.

Base. The layer of compacted crushed stone under pavers, a wall or a slab. It carries the load and drains water.

Batter. The backward lean of a retaining wall into the slope it holds. Also called setback.

Bedding sand. The thin layer of coarse sand, usually 1 inch, that pavers are laid on.

Blocking. Short pieces of lumber fixed between joists to stiffen them or to support the ends of deck boards.

Bulk. Material sold loose by the cubic yard or the ton, as opposed to in bags.

Bulking. The increase in volume when soil is dug up and loosened. Excavated soil takes up roughly a quarter more space than it did in the ground.

Butt joint. Where two boards meet end to end. On a deck, each butt joint must sit over a joist.

Cap. A flat finishing block glued to the top course of a block wall.

Coir. Fiber from coconut husks, used in soil mixes to hold water. An alternative to peat moss.

Cold joint. A weak seam formed when fresh concrete is poured against concrete that has already begun to set.

Compaction. Pressing material together to remove air, usually with a plate compactor or tamper. Compacted base is far stronger than loose base, and takes up about 15% less volume.

Compost. Decomposed organic matter used to improve soil structure and supply nutrients.

Course. One horizontal row of blocks or bricks in a wall.

Crown. The point where a plant’s stems meet its roots, at soil level. Mulch should be kept off it.

Crusher run. Crushed stone containing a full range of particle sizes down to dust, so that it locks together when compacted. Also sold as road base, dense graded aggregate or paver base.

Cubic foot. A volume 1 foot long, wide and high. The unit bags are usually labeled in.

Cubic yard. A volume 3 feet long, wide and high, equal to 27 cubic feet. The unit bulk materials are sold in. Often just called a yard.

Cure. The chemical hardening of concrete over days and weeks. Concrete cures, it does not simply dry.

D to L

Decomposed granite. Granite weathered into fine, gritty particles. It compacts into a firm surface for paths and patios.

Density. Weight per unit of volume, such as pounds per cubic yard. Used to convert a volume of stone into tons.

Drainage aggregate. Clean, angular crushed stone with no fine particles, placed behind a retaining wall so that water can drain away.

Edge restraint. A rigid plastic, metal or concrete border spiked around a paved area to stop the pavers from spreading.

Fall. The slope built into a surface so that water runs off, usually given in inches per foot.

Fines. The smallest particles in a crushed stone product, down to dust. Fines help a base lock together and are unwanted in drainage stone.

Footing. A block or strip of concrete in the ground that supports a post, wall or structure.

Frost heave. The lifting of soil, posts and paving as water in the ground freezes and expands.

Frost line. The depth to which the ground freezes in winter in a given place. Footings and post holes go below it.

Geotextile. A tough fabric laid between soil and stone to keep them from mixing while letting water through.

Grade. The level and slope of the ground. To grade is to shape it. For fertilizer, the grade is the analysis.

Hardscape. The built, non-living parts of a landscape: paving, walls, steps and edging.

Herringbone. A paving pattern in which rectangular pavers are laid in a zigzag at right angles to each other. Strong, and wasteful at the edges.

Joist. One of the parallel framing members that deck boards are fastened to.

Landscape fabric. A woven or non-woven sheet laid under gravel or mulch to suppress weeds, or behind walls to separate soil from stone.

Ledger. The board that attaches a deck to the house and carries one end of the joists.

Linear foot. One foot of length, regardless of width. Lumber, edging and pipe are priced this way.

Loam. Soil with a balanced mix of sand, silt and clay. The ideal garden soil.

M to R

Mulch. Any material spread over soil to hold moisture, suppress weeds and moderate temperature. Organic mulches rot down. Stone mulches do not.

Nominal size. The name a piece of lumber is sold under, which is larger than its actual size.

N-P-K. Nitrogen, phosphorus and potassium, the three main plant nutrients, in the order they appear on a fertilizer label.

On center. A way of measuring spacing, from the middle of one joist or post to the middle of the next. Abbreviated o.c.

Overseeding. Sowing grass seed into an existing lawn to thicken it. Uses about half the new-lawn rate.

Pallet. The wooden platform that sod, pavers, block and bags are stacked and delivered on. Also used loosely as a unit of quantity.

Payload. The maximum weight a vehicle can carry, including passengers. Printed on a sticker inside the driver’s door.

Perlite. A lightweight white volcanic material added to soil mixes to improve drainage and aeration.

Pitch. Another word for slope. On a deck, also the distance from the middle of one board to the middle of the next.

Plate compactor. A machine with a heavy vibrating plate, rented for compacting base material.

Polymeric sand. Fine sand with a binder that hardens when wetted, swept into paver joints to lock them and resist weeds.

Rail. A horizontal member of a fence, running between posts, to which boards or pickets are fixed.

Ready-mix. Concrete mixed at a plant and delivered by truck, as opposed to mixed on site from bags.

Rim joist. The joist that runs around the outside edge of a deck frame, closing off the ends of the other joists.

Running bond. A paving or walling pattern in which each row is offset by half a unit from the row beside it, like brickwork.

S to Z

Screed. To level a layer of sand or concrete by dragging a straight board across guides. Also the board itself.

Screened. Passed through a mesh to remove stones, roots and lumps. Screened topsoil is easier to spread.

Setback. The distance each course of a retaining wall steps back from the one below. Also, the distance a structure must be kept from a property line.

Short-load fee. A charge added by ready-mix plants for delivering less than a minimum quantity.

Slump. A measure of how wet and workable fresh concrete is.

Sod. Grass and the layer of soil held by its roots, cut into rolls or slabs for laying. Called turf in some countries.

Spoil. Soil and debris dug out of the ground during a project, which has to be reused or removed.

Square. In paving and roofing, 100 square feet. In layout, a corner of exactly 90 degrees.

Subgrade, subsoil. The native ground beneath the topsoil, on which a base is built.

Tamp. To compact by repeated blows, with a hand tamper or a bar.

Ton, tonne. A US ton is 2,000 pounds. A metric tonne is 1,000 kilograms, about 2,205 pounds.

Top-dressing. Spreading a thin layer of compost, soil or sand over a lawn or bed without digging it in.

Topsoil. The upper layer of soil, containing most of the organic matter and biological activity. Sold screened for garden use.

Vermiculite. A mineral expanded by heat into light, spongy flakes that hold both water and air in a soil mix.

Waste factor. The percentage added to a measured quantity to cover cutting, breakage, settling and uneven ground.

Yard. In landscape supply, a cubic yard. Three feet in each direction, or 27 cubic feet.

Last reviewed October 4, 2026. If a term in one of our guides is not explained here, tell us and we will add it.