Nitrogen (N)
The first number in an NPK fertilizer ratio. Nitrogen drives leaf and blade growth and is responsible for the deep green color of healthy turf. It is the nutrient lawns need most, but too much can cause rapid, weak growth and increase disease risk.
Nitrogen (N) is the primary driver of lawn growth and color. It is the first number in any fertilizer ratio (e.g., the "28" in 28-0-6). Grass needs more nitrogen than any other nutrient.
Slow-release vs quick-release: Quick-release nitrogen (ammonium nitrate, urea) gives fast green-up but can burn and must be watered in immediately. Slow-release nitrogen (polymer-coated, sulfur-coated, IBDU) feeds gradually over 6–12 weeks.
Too much nitrogen: Leads to excessive, soft blade growth, increased disease susceptibility, and reduced root development. More is not better.
More on Fertilizer
Put this into practice
SimpleLawn is a free iPhone app. Map your lawn, track treatments, and get advice tailored to your yard.
Prefer your computer? Use the web app