Glossary
Plain-language definitions of the terms used across Lawn by Soil.
- Calibration
- Measuring how much a spreader or sprayer actually applies, so label rates can be followed accurately. Read more
- Cool-season grass
- Grasses such as Kentucky bluegrass, tall fescue, fine fescues and perennial ryegrass that grow most in spring and fall.
- Crabgrass
- A summer annual grassy weed that germinates in spring as soil warms and dies with the first frost, after setting seed.
- Dormancy
- A resting state when grass stops growing, from cold (warm-season grass in winter) or heat and drought (cool-season grass in summer).
- Green-up
- The spring return to active growth and color, especially used for warm-season grasses coming out of dormancy.
- Mesonet
- A network of automated weather stations, often run by a state or university, that may report soil temperatures at set depths.
- N-P-K
- The three numbers on a fertilizer bag, giving the percentage by weight of nitrogen (N), phosphate (P2O5) and potash (K2O). Read more
- Overseeding
- Sowing seed into an existing thin lawn rather than bare soil. Uses a lower rate than a new lawn. Read more
- Pounds of N per 1,000 sq ft
- The standard way lawn fertilizer guidance is written. Divide by the bag's nitrogen percentage (as a decimal) to get pounds of product.
- Pre-emergent herbicide
- A product that stops weed seeds from developing as they germinate. It does not control weeds already growing. Timing is critical. Read more
- Pure live seed (PLS)
- Purity multiplied by germination, from the seed tag. The share of the bag's weight expected to become plants of the named grass.
- Seeding rate
- Pounds of seed per 1,000 square feet. Depends on species because seed sizes differ.
- Soil temperature
- The temperature of the soil at a stated depth. Lawn timing research usually specifies the depth (often 1–2 or 4 inches) and sometimes the time of day. Read more
- Warm-season grass
- Grasses such as bermudagrass, zoysiagrass, St. Augustinegrass, centipedegrass and buffalograss that grow in summer and go dormant in winter.
- Watering in
- Applying about enough water (or timing rain) to move a granular product off the grass blades and into the soil, as the label directs.