Lawn Care Schedule
Your grass type and ZIP code give you a dated twelve month lawn schedule, with every timing conflict flagged.
Build your schedule
Jobs you plan to do this year
Mowing and feeding are always shown. Tick the rest and the schedule checks them against each other. This is where the pre-emergent problem shows up.
How these dates are calculated
Every date on this page is an offset from your two frost dates, because soil temperature is what actually drives turf, and frost dates are the closest thing to a soil temperature calendar that everybody already knows for their own address. Your ZIP code returns an average last spring frost and an average first fall frost, and each job is placed a fixed number of days before or after one of them.
Worked example for a tall fescue lawn with a last frost of April 20 and a first frost of October 25: the fall seeding window is first frost minus 70 days to first frost minus 45 days, which is August 16 to September 10. Forty-five days is the accepted minimum for a cool-season seedling to root well enough to survive its first winter, and seventy days back from frost is roughly when night temperatures stop cooking new seedlings.
The offsets themselves come from the standard turf calendars published by state cooperative extension turf programs, which agree closely on the shape of the year even when they differ on exact dates. Where a figure genuinely varies, this page gives the range rather than a false-precision single number. Two things the tool cannot know are your soil temperature this particular year and your actual thatch depth, so treat every date as the middle of a window, not a deadline.
The one rule that overrides the calendar: pre-emergent herbicide does not know the difference between a crabgrass seed and a grass seed. Applying it blocks both. That is why this tool asks which jobs you plan before it hands you dates.
Grass type quick reference
Rates below are reference figures, not the output of this tool. This page answers when. Use the rates to sanity check a bag label, and follow the label when the two disagree.
| Grass | Season | USDA zones | Mow height | New seed | Overseed | Annual N |
|---|---|---|---|---|---|---|
| Kentucky bluegrass | Cool | 3 to 7 | 2.5 to 3.5 in | 2 to 3 lb | 1 to 1.5 lb | 2 to 4 lb |
| Tall fescue | Cool | 4 to 7 | 3 to 4 in | 6 to 8 lb | 3 to 4 lb | 2 to 3 lb |
| Perennial ryegrass | Cool | 4 to 7 | 2 to 3 in | 6 to 9 lb | 4 to 6 lb | 2 to 4 lb |
| Fine fescue | Cool | 3 to 7 | 2.5 to 4 in | 4 to 5 lb | 2 to 3 lb | 1 to 2 lb |
| Bermuda | Warm | 7 to 10 | 0.75 to 2 in | 1 to 2 lb hulled | 0.5 to 1 lb | 3 to 5 lb |
| Zoysia | Warm | 6 to 10 | 1 to 2.5 in | 1 to 2 lb | Not practical | 1 to 3 lb |
| St. Augustine | Warm | 8 to 11 | 2.5 to 4 in | No seed sold | Sod or plugs only | 2 to 4 lb |
| Centipede | Warm | 7 to 9 | 1.5 to 2.5 in | 0.25 to 0.5 lb | 0.25 lb | 0.5 to 1 lb |
St. Augustine is not sold as seed in the United States in any commercially useful form, so every St. Augustine job on this page is sod, plugs or sprigs. Centipede is the opposite problem: it is the one common lawn grass that is genuinely damaged by normal fertilizer rates, and overfeeding it is the usual cause of centipede decline.
How long pre-emergent blocks grass seed
This is the table the conflict warning is built on. Intervals vary with rate, product and soil temperature, so the ranges below are ranges on purpose. The number that counts is on your own product label.
| Active ingredient | Common product names | Wait before seeding | Notes |
|---|---|---|---|
| Prodiamine | Barricade and generics | About 12 to 16 weeks | Longest residual of the common ones. At a full spring rate it can still be blocking seed in early fall. |
| Dithiopyr | Dimension and generics | About 12 weeks | Also kills very young crabgrass, which prodiamine will not do. |
| Pendimethalin | Pre-M, Scotts Halts | About 8 to 12 weeks | Shortest of the three, so it is the easiest to fit around a seeding date. |
| Siduron | Tupersan | None, seed the same day | The exception. It is safe over new seed, but it is expensive and controls a narrower list of weeds. |
| Mesotrione | Tenacity | None on listed species | Labeled for application at seeding on several common turf grasses. Check that yours is on the label. |
| Corn gluten meal | Various organic brands | About 6 weeks | Organic does not mean seed safe. It works by stopping root formation in germinating seed, including yours. |
Keep planning
The same frost dates that built this schedule drive the rest of the yard.
Common questions
Can I put down pre-emergent and grass seed at the same time?
With ordinary pre-emergent, no. Products based on prodiamine, dithiopyr, pendimethalin or corn gluten meal work by killing the root as it emerges from a germinating seed, and they cannot tell your grass seed from a crabgrass seed. Seed sown into that barrier germinates and then dies, which is why people conclude they bought bad seed.
There are two real exceptions. Siduron is labeled for use at seeding, and mesotrione is labeled for application at seeding on several common turf species. Both cost more and cover a narrower weed list than a standard pre-emergent. If you are seeding this year, the simplest answer is usually to skip pre-emergent in that season and pull or spot-treat the crabgrass instead.
How long after pre-emergent can I seed?
Roughly 8 to 16 weeks, depending entirely on which active ingredient you used and at what rate. Pendimethalin is usually the shortest at about 8 to 12 weeks, dithiopyr about 12 weeks, and prodiamine the longest at 12 to 16 weeks. A full spring rate of prodiamine can still be blocking seed when the ideal fall seeding window opens.
The interval is printed on the label for the exact rate you applied, and it is the only figure you should trust over an online table. Core aerating before you seed helps break the barrier physically, but it does not reset the clock.
Why do cool-season and warm-season lawns have opposite calendars?
Because they grow at different temperatures. Cool-season grasses such as tall fescue and Kentucky bluegrass do their best root work between roughly 60 and 75 degrees Fahrenheit, which means spring and fall, and they simply survive the summer. Warm-season grasses such as bermuda and zoysia do their best work between roughly 80 and 95 degrees, so they are dormant and brown when a fescue lawn is at its greenest.
That flips the two most important jobs. Cool-season lawns are seeded and fed hardest in late summer and fall. Warm-season lawns are seeded and fed in late spring and early summer, and feeding them late in the fall is a genuine way to get winterkill.
I live in the transition zone. Which schedule do I follow?
Follow the schedule for the grass you actually have, not the one for your zone. The transition zone, roughly USDA zones 6 and 7, is uncomfortable for both types, which is exactly why both are grown there. A tall fescue lawn in Kentucky still gets the cool-season fall calendar, and a bermuda lawn two streets over still gets the warm-season summer calendar.
If you are choosing from scratch in the transition zone, tall fescue and zoysia are the two that hold up best at either end of it, and both are widely grown there.
Should I aerate and overseed at the same time?
For a cool-season lawn, yes, and it is the single most effective thing on this schedule. Core aeration pulls plugs and leaves open holes with soil-to-seed contact already made, which is most of what determines whether seed takes. Do the aeration first, then spread the seed, then leave the plugs to break down.
For a warm-season lawn the timing is different but the pairing still works: aerate in late spring or early summer during active growth, not in the fall, because a warm-season lawn heading into dormancy cannot heal the holes.
Do I need to dethatch every year?
Almost certainly not. Dethatching is a repair, not maintenance. Push a finger or a knife into the lawn and measure the spongy brown layer between the green blades and the soil. Under half an inch is healthy and doing useful work holding moisture. Over half an inch is worth dealing with, and over an inch is a real problem.
Thatch is mostly a warm-season and Kentucky bluegrass issue because those grasses spread by stolons and rhizomes. Tall fescue is a bunch grass and rarely builds meaningful thatch at all. Core aeration handles a mild thatch layer with far less damage than a power rake.
When is the last safe date to seed in the fall?
About 45 days before your average first frost for a cool-season lawn. A seedling needs roughly six weeks to put down enough root to survive being heaved by freeze and thaw cycles over winter. Seed later than that and a good share of it germinates, looks fine in November, and is gone by March.
This tool puts that date on your timeline. Because the frost date behind it is a regional average, treat the last two weeks of the window as a gamble rather than a plan.
How accurate are these dates for my street?
They are as accurate as the frost dates underneath them, which are regional averages for your three-digit ZIP area. Local microclimate, elevation and normal year-to-year variation move real frost dates by one to two weeks in either direction, and every date on this schedule moves with them.
Use the schedule to plan the order of jobs and to catch conflicts, then let soil temperature make the final call. Your county cooperative extension office publishes local turf calendars and will answer questions for free.