Category: Mowing & Watering

Mowing height is the single cheapest lever you have. It costs nothing, you already own the equipment, and getting it right prevents more weed and drought problems than any product you can buy.

Most Tuscaloosa lawns are cut too short.

Alabama Extension’s numbers

Extension’s Home Lawn Maintenance page publishes what amounts to the canonical table for Alabama:

Grass	Recommended mowing height
Bermudagrass	1 to 2 in.
Centipedegrass	1 to 2 in.
Zoysiagrass	1 to 2 in.
St. Augustinegrass	2.5 to 4 in.
Tall fescue	2 to 3.5 in.

Worth knowing: Extension’s own species-specific guides publish somewhat different ranges. Their bermudagrass guide says 1.5 to 2.5 inches for home lawns. The zoysia guide says 1.5 to 3 inches. The older centipede publication says 1 to 1.5 inches. These are not typos, they are genuine inconsistencies across Extension publications written at different times.

Practical read: anywhere in the union of those ranges is defensible. The failure mode is not being an eighth of an inch off, it is cutting bermuda at three quarters of an inch with a rotary mower because a neighbor does.

The one-third rule, which matters more than the number

Extension states it plainly: “never remove or mow off more than one-third of the turfgrass height in any mowing event.”

This is the rule people break constantly, usually by skipping a week. If you maintain bermuda at 1.5 inches, you should be mowing when it hits about 2.25 inches. Let it reach 3 and cutting back to 1.5 removes half the plant at once.

What that does: the grass dumps root mass to rebalance with the reduced leaf area. Shallow roots mean less drought tolerance, which matters a great deal in a place where August, September and October are the three driest months of the year. It also opens the canopy and lets sunlight reach soil, which is exactly what germinating crabgrass wants.

Scalping a lawn once will not kill it. Scalping it every week all summer produces a thin, weedy, drought-prone lawn, and the owner usually concludes they need more fertilizer.

Why taller is usually better here

More leaf area means more photosynthesis, deeper roots, more shade at the soil surface. In Tuscaloosa’s summer — July normals of 92 degrees by day and 71 at night — that shading effect is doing real work. Bare soil between thin grass blades heats up, dries out and grows weeds.

The exceptions:

• Reel-mown bermuda. Extension notes bermuda can be maintained below half an inch with a reel mower. That is a legitimate maintenance system with its own fertility, irrigation and mowing-frequency requirements. It is not what a rotary mower on a suburban lot is doing.
• Spring scalping. Deliberately dropping the deck before green-up to remove dead thatch and let soil warm is a recognized practice. Extension describes lowering the deck one notch per month and bagging clippings, aiming to hit the lowest setting right as the grass comes out of dormancy. That is a once-a-year event, not a standing height.

Mowing frequency

Extension says bermuda home lawns should be mowed at least once per week. In peak season — May through August, with heat, humidity and nitrogen all working — twice a week is not unreasonable if you want to hold a low height without violating the one-third rule.

Zoysia does not need mowing as often as bermuda. Centipede is slower still. That is a real part of the maintenance calculation when choosing a grass.

Details worth getting right

Keep the blade sharp. A dull rotary blade tears rather than cuts. The ragged tips brown out within a day or two and give the whole lawn a grey cast, and the wounds are entry points for disease.

Leave the clippings. They are mostly water, they break down quickly, and they return nitrogen. Clippings do not cause thatch — thatch is built from stems, stolons and roots. The exception is the spring scalp, where you are removing dead material and should bag it.

Watch the thatch layer anyway. Extension’s April calendar says to dethatch bermuda and zoysia if the layer exceeds half an inch, and to wait for active growth. Their Home Lawn Maintenance page uses a one-inch threshold. Either way, check it in spring rather than discovering it in July.

Change direction. Mowing the same pattern every week trains the grass to lean and compacts the same wheel tracks.

Do not mow wet grass if you can avoid it. It clumps, it cuts unevenly, and it spreads fungal disease around the yard on the deck and tires.

Quick reference

• Bermuda: 1.5 to 2 inches, weekly minimum, twice weekly in peak season
• Zoysia: 1.5 to 2.5 inches, roughly weekly
• Centipede: 1 to 2 inches, every 7 to 10 days
• St. Augustine: 3 to 4 inches, weekly
• Never remove more than one third of the blade in one pass
• Sharpen the blade at least twice a season

The most common irrigation mistake in Tuscaloosa is not watering too little. It is watering a little bit every day.

What Alabama Extension actually recommends

From Home Lawn Maintenance:

Apply about one-half to one inch of water, which will moisten the soil to a depth of 4 to 6 inches. Never water a lawn every day except during the establishment phase or renovation. Frequent watering only encourages shallow rooting.

Weekly totals come from Extension’s species guides:

• Bermudagrass: 1 to 1.25 inches per week on a recurring basis, more during persistent drought
• Zoysiagrass: about one inch of supplemental irrigation during periods of no rainfall
• Centipedegrass: about one inch per week to maintain attractive color
• St. Augustinegrass: roughly half an inch per application, watered early while dew is still on the lawn

So: roughly an inch a week, delivered in one or two soakings, not seven sprinkles.

Why deep and infrequent works

Roots grow toward water. Water the top inch of soil every evening and roots have no reason to go deeper than an inch. That lawn is completely dependent on you — miss three days in August and it browns.

Water to 4 to 6 inches once or twice a week and roots follow. That lawn has a buffer. It survives a missed week, a broken timer, a vacation.

Extension’s exception is establishment. New sod or sprigs do get daily water — St. Augustine wants daily irrigation for at least two weeks after planting, and newly sodded centipede gets about half an inch per irrigation daily the first week, then only as needed. That is a temporary phase, and it is where a lot of people form a daily-watering habit they never break.

Morning, not evening

Extension: “The best time of the day to irrigate or water is early in the morning because it minimizes the potential for water loss through evaporation.” Their south Alabama calendar narrows it to 6:00 a.m. to 10:00 a.m.

Evening watering leaves the canopy wet overnight. In Tuscaloosa’s humidity that is a standing invitation to fungal disease — brown patch, large patch, dollar spot all favor extended leaf wetness.

Calibrating, which takes ten minutes once

You cannot manage an inch of water if you do not know what an inch looks like from your system. Extension’s method, verbatim:

Scatter a few shallow empty cans, such as from canned chicken or tuna, around the irrigated area to measure the length of time your system takes to apply one-half to one inch of water.

Run the zone, time it, measure the depth in the cans, average them. Now you know your zone puts down, say, half an inch in 22 minutes. You are done guessing forever.

The scattered cans also reveal coverage problems — if one can has twice what another does, you have a head or pressure issue that no amount of run time fixes.

The Tuscaloosa wrinkle: the fall dry spell

Tuscaloosa averages 52.60 inches of rain a year, which sounds like a lot. The problem is when it falls.

Using NOAA 1991 to 2020 normals for Tuscaloosa Municipal Airport, the three driest months are August (3.30 in.), September (3.52 in.) and October (3.51 in.). The wettest are November through February — 5.08, 4.62, 5.35 and 5.32 inches — when warm-season turf is dormant and indifferent.

That inversion is the local story. Rainfall bottoms out exactly when the lawn is still actively growing, still hot, and heading into fall pre-emergent and armyworm season. Irrigation demand in Tuscaloosa peaks in late summer and early fall, not midsummer, and a lot of people mentally check out of lawn care right as it matters most.

Runoff on sloped lots

Much of Tuscaloosa County sits in the Fall Line Hills, where the Geological Survey of Alabama notes topography can be fairly rugged with steep slopes occurring near streams. Coastal Plain soils here are typically sandy over a clayey subsoil.

On a slope, a long single run produces runoff — water leaving before it soaks in. The fix is cycle-and-soak: split the run into two or three shorter cycles with 30 to 60 minutes between them. Same total volume, all of it absorbed.

Are there watering restrictions in Tuscaloosa?

Not on a standing, year-round basis, as far as published city material shows.

Tuscaloosa adopted a five-stage drought contingency policy in 2017. Stage 1 triggers when Lake Tuscaloosa drops 11 feet below pool level, and the Stage 1 response is a request for voluntary conservation. At adoption, city officials noted that a drought severe enough to trigger it would be several times worse than anything on record, and that the plan was more likely to be activated by infrastructure failure than by weather.

The city has issued temporary orders before — in June 2021 a conservation order restricted non-essential water use for customers south of the Black Warrior River, then expired.

The current City of Tuscaloosa water pages do not publish drought stages or watering rules. Check the city’s water page for any active order before assuming, and treat any article listing specific odd/even watering days for Tuscaloosa with suspicion — that text is not published anywhere we could find.

Signs you are getting it wrong

Underwatered: footprints stay visible after you walk across, blades fold along the midrib, color goes blue-grey before it goes brown.

Overwatered: spongy underfoot, mushrooms, algae or moss in low spots, recurring fungal patches, shallow roots you can peel up like carpet.

Just right: the lawn goes a week between waterings in summer without complaint, and a screwdriver pushes into the soil easily to four inches the day after you water.

Quick reference

• One inch per week total, from rain plus irrigation
• One or two applications, never daily except on new sod
• Early morning, ideally 6 to 10 a.m.
• Wet the soil 4 to 6 inches deep
• Calibrate with tuna cans once and stop guessing
• Cycle and soak on slopes
• Expect the heaviest demand August through October, not July