# When and how to fertilize your lawn

Updated: 2026-10-24 · https://pros411.com/en/guides/landscaping/when-to-fertilize-lawn

## Short answer

Feed it when your type of grass grows best. Cool-season grass like tall fescue or Kentucky bluegrass gets its main feeding in early fall. Warm-season grass like Bermuda, St. Augustine or zoysia gets fed from late spring through summer. Use a spreader at the rate on the bag, sweep stray granules off the pavement and water it in lightly.

> Safety first: Fertilizer is a chemical. Wear gloves, read the label, store the bag where kids and pets cannot reach it, and keep them off the lawn until it is watered in and dry.

## How to fertilize your lawn at the right time

![Cartoon lawn asking if it is time to be fed, next to a fertilizer bag and a spreader](https://pros411.com/img/guias/when-to-fertilize-lawn.webp)

1. **Feed it when your grass grows.** Cool-season grass like fescue gets its main feeding in early fall. Warm-season grass like Bermuda or St. Augustine gets fed from late spring through summer.
2. **Read the bag and set the spreader.** The three numbers are nitrogen, phosphorus and potassium. Set the spreader dial to the setting the bag gives for your model. More is not better.
3. **Spread half one way, half across.** Walk at a steady pace on dry grass. For an even coat, use half the rate and go over the lawn twice, the second time crosswise.
4. **Sweep the pavement, then water it in.** Sweep granules off the sidewalk and driveway back onto the grass, so rain does not wash them into the storm drain. Then water lightly, unless the label says not to.
5. **A thicker lawn that crowds out weeds.** Keep kids and pets off until it dries. Most lawns need two to four feedings a year. Leave the clippings: they give some of the food back.

## Feeding calendar by grass type

- Cool-season grass (tall fescue, Kentucky bluegrass, ryegrass), common in the North: the main feeding in early fall. Add an optional one in late fall and a light one in late spring. Skip the summer heat.
- Warm-season grass (Bermuda, St. Augustine, zoysia, centipede), common in the South: start in late spring, once you have mowed it two or three times. Feed every 6 to 8 weeks through summer and stop about 6 weeks before your first frost.
- Not sure which grass you have? Ask your county extension office or a local garden center. Many extension offices also run soil tests.
- Some cities and counties, including many in Florida, ban fertilizer with nitrogen or phosphorus during the summer rainy season. Check your local rules first.

## What not to do

- Do not feed warm-season grass in early spring, before it is growing. The weeds get the food.
- Do not fertilize dormant or drought-stressed grass in the summer heat.
- Do not spread it right before a heavy rain. It washes off the lawn and into the street.
- Do not overlap passes or spill the bag. Too much burns the grass in stripes or spots that feel dry and crisp.
- Do not use weed and feed near trees, shrubs or a vegetable garden unless the label allows it.

## If you see fertilizer burn

Burned grass shows up a few days after feeding, in stripes or spots that dry out and crunch underfoot. Water the area deeply every day for about a week to flush the extra out of the soil. Most of it recovers. Spots that stay bare need seed or a piece of sod.

## When to call a landscaper

- You fertilize on schedule and the lawn still looks thin and weak.
- Burned stripes or spots do not recover after a week of deep watering.
- You are not sure what grass you have or what your soil needs.
- You want a yearly feeding and weed plan handled for you.

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## Frequently asked questions

### What month should I fertilize my lawn?

It depends on your grass and where you live. Cool-season lawns get their main feeding in early fall, often September. Warm-season lawns get fed from late spring, often May, through late summer.

### How often should I fertilize my lawn?

Most lawns do well with two to four feedings a year. Follow the rate on the bag and space them out, usually 6 to 8 weeks apart in the growing season.

### Should I water after fertilizing?

Yes, for most granular fertilizers. A light watering moves the granules down into the soil. Some weed and feed products need to sit on wet leaves first, so read the label.

### Can you fertilize your lawn in the summer?

Warm-season grass, yes, as long as it gets enough water. Cool-season grass, avoid it in the heat: it stresses the lawn and can burn it.

### What do the three numbers on fertilizer mean?

They are the percent of nitrogen, phosphorus and potassium, always in that order. Nitrogen does most of the work on a lawn, so lawn fertilizers usually have the biggest first number.

### Is it better to fertilize before or after rain?

A light rain before or after is fine. Avoid fertilizing when heavy rain is on the way, because it washes the granules off the lawn and into storm drains.