When to Fertilize Your Lawn: A Simple Schedule by Grass Type

Knowing when to fertilize your lawn is the key to thick, green grass. Feed too early and you waste money. Feed too late and you invite weeds or disease. The right schedule depends on your grass type and your climate. This guide gives you a simple plan for the whole year.

Know Your Grass Type First

Grass falls into two groups, and each grows at different times.

• Cool-season grasses such as fescue, bluegrass and ryegrass grow fastest in spring and fall.
• Warm-season grasses such as Bermuda, zoysia and St. Augustine grow fastest in summer.

Feed grass when it grows actively. Otherwise, it cannot absorb the nutrients.

When to Fertilize Your Lawn: Cool-Season Grass

Most experts recommend four feedings spread across the year.

1. Early spring: apply a light feeding once the grass turns green. This step wakes up the lawn.
2. Late spring: add a second feeding to support growth before summer heat.
3. Early fall: apply a full feeding. This is the most important one, because it builds roots.
4. Late fall: make a final application before the ground freezes. It helps the lawn green up fast next spring.

Skip heavy feeding in midsummer. Heat stresses cool-season grass, and extra nitrogen can burn it.

When to Fertilize Your Lawn: Warm-Season Grass

Warm-season grass needs food later in the year.

1. Late spring: start once the grass is fully green and soil reaches about 65°F.
2. Early summer: add a second feeding to keep growth strong.
3. Late summer: make a final application at least six weeks before the first expected frost.

Avoid feeding warm-season grass in fall. Fresh growth can suffer winter damage.

How Much Fertilizer to Use

Read the label first. Most lawns need about one pound of nitrogen per 1,000 square feet per application. To find the right amount, measure your lawn and divide the nitrogen percentage on the bag into 100. For example, a 20-percent nitrogen bag needs five pounds per 1,000 square feet.

Test Your Soil

A soil test shows pH and nutrient levels. Contact your local extension office for a low-cost kit. Test results tell you whether you need lime, phosphorus or potassium, so you stop guessing.

How to Apply Fertilizer

1. Mow the lawn a day or two before.
2. Fill a broadcast or drop spreader and set it to the label rate.
3. Walk at a steady pace in overlapping rows.
4. Sweep spilled granules off driveways and sidewalks.
5. Water lightly to move the fertilizer into the soil.

Common Fertilizing Mistakes

• Applying fertilizer before heavy rain, which causes runoff
• Using too much, which burns grass
• Feeding dormant or drought-stressed lawns
• Skipping the soil test

Runoff pollutes waterways, so apply carefully. The EPA offers tips on protecting water quality in your yard.

Pair feeding with good overseeding, as explained in our guide on when to plant grass seed. Healthy grass also helps you get rid of crabgrass.

Final Thoughts

When to fertilize your lawn comes down to your grass type. Feed cool-season grass in spring and fall. Feed warm-season grass from late spring through summer. Follow the label, test your soil and your lawn will reward you with thick, deep-green growth.