When should I do the first cut of the year?

When the grass has grown about a third taller than the height you want to keep it at, and the soil is dry enough that walking on it leaves no footprints. Growth decides it, not the date.

How low should the first cut of spring be?

Slightly lower than your normal height for one cut only, around 2.5 inches for cool-season grass. That clears winter debris and lets light reach the soil. Then raise the deck back up.

Should I mow before or after fertilizing in spring?

Mow first. It removes dead material, shows how much of the lawn has greened up, and means the fertilizer reaches soil instead of sitting on a layer of winter thatch.

Do I need to sharpen the blades before the first mow?

Yes. Dull blades tear grass instead of cutting it, and torn tips brown within a day or two. That is why some lawns look scorched immediately after their first cut of the year.

The First Mow of Spring: When, and How Low

Take the first cut when the grass is about a third taller than your target height and the ground is firm enough to walk on without leaving prints. For most lawns that falls somewhere in March or April, but the grass decides, not the month.

Two conditions, both required

The grass is growing. A single warm week is not growth. You want the lawn visibly putting on height, which means soil has warmed enough for roots to be active.

The ground is firm. Mowing saturated soil compacts it under the wheels and tears turf on the turns. If your shoes sink or footprints stay behind, wait. You would be undoing a year of aeration in twenty minutes.

The one-third rule

Never remove more than a third of the blade height in one cut. Take off more and the plant dumps energy into regrowing leaf instead of roots, and the lawn yellows for a week while it does.

The mechanism is simple. Leaf tissue is how the plant makes food, so removing most of it at once forces the plant to spend stored root reserves rebuilding what you just cut off. Do that in early spring, when reserves are already low after winter, and you set the lawn back a month.

If the grass got away from you over a wet fortnight, take it down in two passes a few days apart.

Slightly low, once

The first cut of spring is the one time to go a notch below your normal height, about 2.5 inches for cool-season grass. There is a reason for it. It removes the dead matted material left from winter and lets light and warmth reach soil level, which speeds green-up.

Then put the deck back up. Through the rest of the season, taller is better: 3.5 to 4 inches for cool-season lawns. Tall grass shades the soil, keeps roots cooler, holds moisture, and crowds out crabgrass. It is the most effective free weed control available, and it matters most in the weeks after pre-emergent starts to wear off.

Warm-season lawns are the exception. Bermuda and zoysia are cut much shorter, 1 to 2 inches, and their first cut comes at green-up rather than on the cool-season schedule.

What the first cut tells you

Mowing is a diagnostic. Walk the lawn afterward and look:

Grass that lifts away in sheets. Grub damage from last year. The roots are gone. Confirm with signs of grub damage vs. drought stress.
Spongy, bouncy areas. Thatch. Measure it before deciding anything: why is my lawn spongy.
Gray-pink matted patches. Snow mold, usually from grass left too long over winter. See when to stop mowing to avoid a repeat.
Areas still brown after two weeks of growth elsewhere. Worth diagnosing rather than reseeding blind: why grass turns yellow in patches.

What to do next

Order matters, and most people get it backward:

First mow, which clears debris and shows you what you are working with.
Pre-emergent, timed to soil temperature rather than to the mow.
Fertilizer, after green-up. For warm-season lawns that means not until the lawn is half green.
Watering, which starts later than most people think: how often to water an established lawn.