The plain-English glossary

What does that
lawn word mean?

Lawn advice gets easier when the vocabulary stops getting in the way. Start here, then head back to your plan.

Core aeration

Pulling soil plugs out to relieve compaction. Read the guide ↗

Overseeding

Sowing grass seed into an existing lawn. Read the guide ↗

Thatch

A layer of stems and roots between green grass and soil. Read the guide ↗

Pre-emergent

A weed-control product applied before weed seedlings emerge. Read the guide ↗

Post-emergent

A treatment for weeds that are already growing. Read the guide ↗

Dormancy

A temporary pause in growth during cold or drought. Read the guide ↗

N-P-K

The fertilizer label numbers for nitrogen, phosphorus and potassium. Read the guide ↗

Cool-season grass

Grass that grows best in the cooler parts of the year. Read the guide ↗

Warm-season grass

Grass that grows best in warm weather and often goes dormant in winter. Read the guide ↗

USDA hardiness zone

A measure of average extreme winter cold, not a full lawn calendar. Read the guide ↗

Scalping

Cutting below the grass’s healthy mowing range. Read the guide ↗

Soil pH

A measure of soil acidity or alkalinity. A lab test guides correction. Read the guide ↗