Zoysiagrass Lawn Care Guide for Maryland

The Nitrogen Budget

For zoysiagrass, aim for about 2 pounds of nitrogen per 1,000 square feet across the growing season, and treat 3 pounds as the ceiling — above that, the research this guide draws on shows diminishing turf response and a higher risk of thatch and disease. Zoysiagrass is a slow, low-input grass; it does not need the same feeding schedule as a cool-season lawn.

Push nitrogen through spring green-up and into the active summer growing months. Fall feeding should shift toward potassium instead of nitrogen, since late-season nitrogen softens the grass going into winter and is one of the conditions that invites large patch disease — more on that below.

Maryland's Fertilizer Law

Before any product decision, know the legal frame around it. Maryland's lawn fertilizer law is a statewide statute, not a Tiller recommendation, and it overrides any local ordinance. Homeowners are held to the same rules as licensed lawn care companies — there is no do-it-yourself exemption, and these are legal limits with civil penalties attached, not best practices.

Lawn fertilizer cannot be applied between November 15 and March 1. A single application is capped at 0.9 pound of total nitrogen and 0.7 pound of soluble nitrogen per 1,000 square feet, unless the product is an enhanced-efficiency fertilizer approved by the Maryland State Chemist, and at least 20 percent of the nitrogen in the bag must be slow release. Phosphorus is banned from lawn fertilizer sold in the state outright — the middle number on the bag reads zero — except when a soil test shows a deficiency or the lawn is being newly established, patched, or renovated.

Keep fertilizer at least 15 feet from any waterway, or 10 feet if you're using a drop spreader, a rotary spreader with a deflector shield, or a targeted liquid spray. It is against the law to apply fertilizer to a sidewalk, driveway, or other paved surface, and anything that lands there has to be swept back onto the lawn, not hosed off. Skip the application if heavy rain is forecast, and never use fertilizer as a de-icer.

Mowing Through the Season

Keep zoysiagrass between 1 and 2 inches year-round, with 1½ inches as the target through spring, summer, and fall — that height sits in the sweet spot for density without scalping. Never remove more than a third of the blade in one mow; if the lawn has gotten away from you, step the height down gradually over two or three cuts instead of scalping it back in one pass.

The one exception is a single low reset cut at spring green-up, down to about an inch, which clears out the previous year's dormant thatch and speeds up green-up. Bag the clippings for that one cut, then return to the normal mowing height for the rest of the season.

The Season's Key Windows

Zoysiagrass wakes up on soil temperature, not the calendar, so the two windows that anchor the year are both tied to a soil-temperature trigger rather than a fixed date. A pre-emergent herbicide goes down as soil warms toward 55°F, roughly March 17 to April 14, to head off summer annual weeds before the lawn fills back in. Don't rush nitrogen ahead of that: a warm week in March isn't full green-up, and feeding a lawn that's still half-dormant mostly feeds weeds and risks injuring the grass. Hold fertilizer until green-up is complete, then apply the first feeding once soil is consistently above 65°F.

Seeding or renovating zoysiagrass has one real window: soil reliably between about 65°F and 70°F with warm nights holding, which lands roughly May 20 to July 15. That gives a full growing season to establish before dormancy. Zoysiagrass is a warm-season grass — never seed it in fall.

Later in the season, shift attention to potassium rather than nitrogen, roughly late August into early October, to harden the lawn off before dormancy, and consider a fall pre-emergent as soil cools through about 70°F to catch winter annual weeds like annual bluegrass, henbit, and chickweed — but that product also blocks grass seed, so it's one or the other, not both.

Watering

Aim for about ¾ inch of water a week, split into two deep soakings of about ½ inch each, early in the morning so the lawn dries before nightfall — wet turf overnight invites disease. Watering deep and infrequent trains roots to grow down instead of staying shallow.

In sustained heat, that weekly target climbs: add roughly a quarter inch when highs sit near the mid-80s, and up to about a half inch when three or more days push near 90°F, capped so the soil can actually absorb it rather than running off.

If You've Sprayed Before Seeding

Some herbicide categories leave residue that affects germination, so timing matters if seeding is on the calendar. If you've recently applied a broadleaf herbicide, wait about 6 weeks (42 days) before seeding. If you've recently put down a crabgrass pre-emergent, wait about 12 weeks (84 days) before seeding — that product is designed to stop germination, and it doesn't distinguish between crabgrass and the seed you're trying to establish.

These are conditional rules, not fixed dates — plan backward from whichever seeding window you're aiming for, and check the product label for its own re-seeding interval as well.

Large Patch: Fall's Real Disease Threat

Large patch is the disease that defines fall on a zoysiagrass lawn, and by the time most people notice it, the damage is already done. The symptoms — circular brown or straw-colored patches with an orange-tinged edge — actually show up at spring green-up, which fools people into treating in spring when the infection happened months earlier. The fungus takes hold in fall, as soil temperature falls to about 70°F and below, typically late September into early October, and a preventive fungicide only works applied in that fall window, not in spring when the symptoms appear.

This is a preventive treatment for a lawn with a known history of large patch — not a routine annual step. If your lawn has never had it, scout for it instead of spraying on a schedule. The cultural side matters more than the chemistry: late-season nitrogen, overwatering, poor drainage, and heavy thatch all feed this disease, which is exactly why the schedule's own rule against feeding nitrogen after midsummer doubles as disease control. If you do spray, confirm zoysiagrass is named on the product label — the label is the law.

Gear this schedule assumes

These are affiliate links: Tiller earns a small commission at no cost to you. We only list gear the schedule above already assumes you have — no sponsored picks. Full disclosure.

Rain gauge

Any $10 gauge works. You need it to hit the 0.75 in/week target above without guessing.

Soil thermometer

The seed and pre-emergent windows above are soil-temperature windows — a $15 probe beats calendar guessing.

Broadcast spreader

Needed for even fertilizer and seed rates. A basic rotary spreader covers most lawns.

Oscillating sprinkler + hose timer

Enough to water deeply and consistently if you have no in-ground system.

Smart irrigation controller

Only if you have an in-ground system — a Rachio-style controller automates the watering schedule.

Zoysiagrass rewards patience more than intervention — a steady mowing height, a modest nitrogen budget, and windows timed to soil temperature rather than the calendar do most of the work. Layer Maryland's fertilizer law and the fall large patch window on top of that, and the lawn largely takes care of itself the rest of the year.

More guides

Zoysiagrass in other states

Arkansas · California · Georgia · Illinois · Missouri · North Carolina · South Carolina · Tennessee · Texas · Virginia

Other grasses in Maryland

Kentucky Bluegrass · Tall Fescue