How to Build a Lawn Care Schedule by Grass Type

A lawn care schedule is less a calendar of dates than a set of rules tied to how grass grows. Feed and seed when the grass is actively growing and can use it; ease off when it is stressed by heat or cold; mow and water in a way that builds deep roots. The single most important input is your grass type, because cool-season and warm-season grasses grow at opposite times of year. This guide shows how to build a schedule for each, using calendars published by University of Missouri Extension, University of Minnesota Extension and University of Georgia Extension. Those calendars are written for specific regions, so treat every month below as approximate and confirm timing with your own state’s extension service.

Step 1: Identify your grass type

If you are not sure what you have, a local extension office or garden center can identify a sample. Many older lawns are a mix; build the schedule around the grass that dominates.

Step 2: Get a soil test

Before setting fertilizer rates, test the soil. University of Minnesota Extension notes that phosphorus is often already high in Midwestern soils and advises applying it only if a soil test shows a need, with new lawns as the exception. The test also shows pH and whether potassium or lime is needed. University of Georgia Extension’s advice for warm-season lawns is the same: apply fertilizer and lime based on recent soil test results.

Step 3: Set the fertilizer plan

Cool-season lawns

University of Missouri Extension calls early September the most important fertilizer application of the year for cool-season grass, at 1 to 1.5 pounds of nitrogen per 1,000 square feet, with a second, moderate application in October once days cool. Spring feeding is lighter: about 0.5 to 1 pound in April, preferably slow-release. Missouri advises against applying nitrogen past early May, because summer feeding pushes growth when the grass is heat-stressed.

University of Minnesota Extension sets the yearly total by how the lawn is managed. A lawn that gets some watering and has clippings returned needs about 1 to 2 pounds of nitrogen per 1,000 square feet a year, split between September and May–June. Higher-maintenance lawns need more, and lawns in soil high in organic matter need less. Minnesota’s limit per application is 1 pound of nitrogen per 1,000 square feet.

Warm-season lawns

University of Georgia Extension advises waiting until the lawn has fully greened up, usually May in Georgia, before starting nitrogen. Feeding dormant grass too early can push tender growth that a late cold snap damages. Applications then continue through summer, with rates and numbers depending on the species; UGA publishes separate calendars for bermudagrass, zoysiagrass, centipedegrass and St. Augustinegrass.

Working out the amount of product

Fertilizer bags list nitrogen as a percentage. Missouri Extension’s shortcut: divide 100 by the nitrogen percentage to get the pounds of product that supply one pound of nitrogen per 1,000 square feet. A bag labelled 20 percent nitrogen needs 100 ÷ 20 = 5 pounds of product per 1,000 square feet for a one-pound rate. Measure the lawn’s area once and write it on the schedule.

After spreading, sweep any granules off driveways, walks and gutters back onto the grass. Minnesota Extension notes that fertilizer and clippings left on hard surfaces are a significant source of nutrient runoff into lakes and streams. Water the fertilizer in unless the label says otherwise.

Step 4: Plan seeding and aeration

• Cool-season seeding: late summer to early fall is the best window, per Missouri Extension. Prepare the seedbed in August and seed or sod in September, keeping the soil moist until the grass establishes. Early spring is a second-best option for thin spots.
• Warm-season seeding: May through July, per UGA. New seed or sod needs daily watering for about the first 30 days.
• Core aeration: do it when the grass can recover quickly. Missouri recommends early fall for bluegrass (spring also works where compaction or thatch is a problem); UGA gives May through August for warm-season lawns. Avoid aerating in midsummer heat for cool-season grass.

More detail on thin and bare areas is in lawn repair and lawn aeration.

Step 5: Time weed control

Weed control works when it matches the weed’s life cycle. Missouri Extension’s calendar puts pre-emergent crabgrass control in early spring, before mid-April in central Missouri, and identifies late September as the most effective time to treat perennial broadleaf weeds in cool-season lawns. A thick lawn mowed at the right height is itself the best weed prevention, because it shades out seedlings. Always read and follow the product label, and do not apply pre-emergent products where you plan to seed.

Step 6: Set mowing heights

Mowing too short is one of the most common lawn mistakes. The one rule all three extension services share: never remove more than one-third of the blade at a single mowing.

Raise the height in hot weather: Missouri suggests half an inch to an inch higher for thin cool-season lawns in summer, and UGA suggests about half an inch for warm-season grass in heat. Return clippings to the lawn where possible; Minnesota Extension notes that doing so returns nutrients and lowers the fertilizer the lawn needs. See lawn mowing.

Step 7: Water deeply and less often

Both Missouri and Georgia put an established lawn’s need at about one inch of water a week, including rain. Missouri recommends applying it two to three times a week rather than daily, wetting the soil to about six inches, and watering in the early morning. Shallow daily watering keeps roots near the surface. A rain gauge or a few straight-sided cans on the lawn show how long your sprinkler takes to deliver an inch. See lawn watering.

Putting it together

A simple schedule fits on one page. For a cool-season lawn in a mid-latitude climate, based on Missouri’s calendar:

For warm-season grass, the active season shifts later: green-up in spring, feeding and aeration from late spring through summer, seeding May through July, and no nitrogen as the grass heads into dormancy. Season-by-season detail is in seasonal lawn care and lawn fertilization, and all lawn guides are collected under lawn care.

Sources

• University of Missouri Extension: Cool-Season Grass Lawn Calendar (G6705)
• University of Minnesota Extension: Fertilizing lawns
• University of Georgia Extension, Fulton County: May Lawn Care Update