Planting Calendar by Zone: How to Build Your Own

Updated August 2026 · Garden Advice Guide

A planting calendar is just three numbers turned into dates: your average last spring frost, your average first fall frost, and each crop's days to maturity. Everything else, every "start tomatoes 6 weeks early" rule you've ever read, is arithmetic built on those three numbers. Which is exactly why a generic national calendar that says "plant tomatoes in April" is worse than no calendar at all, because April 10 is right in Savannah and a dead seedling in Duluth.

Skip the math if you want. Our free planting calendar takes your zip code and prints every sowing, transplant, and fall planting date for your garden.

Updated August 2026

The rest of this page teaches you to build and read the calendar yourself, so you can adjust it when your spring runs late, when you buy a 95-day variety instead of a 70-day one, or when you decide in July that you still want a fall crop.

Why a National Planting Calendar Doesn't Work

Look at two US gardens on the same date. Athens, Georgia averages its last spring frost in late March. International Falls, Minnesota averages its last spring frost in late May. That's a two-month gap on the same continent, and it means the same magazine page telling both gardeners to "set out tomatoes in mid-April" hands one a head start and the other a compost pile.

The gap runs the other way in fall, too. Some Gulf Coast gardens go a full calendar year without a freeze. Zone 3 gardens can see their first fall frost in the first week of September. Between those extremes, the growing season ranges from roughly 90 days to 365.

So any calendar that isn't anchored to your location is guessing. The fix is to anchor it to two local dates and let the math do the rest.

One important correction while we're here, because this trips up almost everyone: your USDA hardiness zone does not tell you your frost dates. The USDA Plant Hardiness Zone Map is built from average annual extreme minimum winter temperature. It tells you whether a shrub survives your winter. It says nothing about when spring arrives. Coastal Seattle and northern Alabama share zone 8b, and their spring planting dates are weeks apart.

Zone is a useful shorthand and we use it below for grouping. But frost dates are the real input, and you look those up separately.

The Three Numbers Behind Every Planting Date

Here they are, and where to get them.

1. Average last spring frost. The date after which you have a 50 percent chance of no more 32°F nights. NOAA's National Centers for Environmental Information publishes freeze and frost date normals by weather station, and most extension offices republish them county by county. Write yours down.

2. Average first fall frost. Same idea in reverse. Your growing season is the number of days between the two.

3. Days to maturity (DTM). This is on the seed packet, and it's the single most-ignored number in gardening. Read it carefully, because DTM is counted from direct sowing for crops you seed in place (beans, carrots, radishes) and from transplant day for crops you start indoors (tomatoes, peppers, broccoli). A tomato packet that says 75 days means 75 days after the seedling goes in the ground, not 75 days after you sowed the seed in February.

That's it. Feed those three numbers into two simple formulas and you have a complete vegetable planting schedule.

Spring Math: Counting Backward and Forward From Last Frost

Spring dates are all expressed as an offset from your last frost date. Some crops go out before it, some after it, and the offset is a property of the crop's cold tolerance.

Indoor start date = last frost date minus (weeks before last frost)

Outdoor date = last frost date plus or minus (weeks per crop)

Frost-hardy crops (peas, spinach, lettuce, radish, kale, broccoli, onions) go out 2 to 6 weeks before last frost. They handle light freezes and they actually taste better in cool weather.

Frost-tender crops (tomatoes, peppers, beans, squash, cucumbers, melons, corn, basil) go out on or after last frost. Peppers and eggplant like an extra two or three weeks of warm soil beyond that.

Here's a real spring for zone 6a with an April 25 last frost:

Notice how the "start peppers indoors" date lands in February, seven weeks before you'd start thinking about spring. That's the whole reason to build the calendar in January instead of in May.

Fall Math: Counting Backward From First Frost

Fall is where most vegetable planting schedules fall apart, because the arithmetic runs the opposite direction and includes a correction factor almost nobody mentions.

Fall sowing date = first frost date minus DTM minus 14 days

That last 14 days is the fall factor. In September, days are getting shorter and cooler, and plants grow measurably slower than the seed packet's summer-tested DTM assumes. A 55-day lettuce sown August 15 is not ready in 55 days. Adding roughly two weeks (some gardeners use 10 days, some use 21 for very late plantings) absorbs that slowdown.

Here's the same zone 6a garden working backward from an October 15 first frost:

For that broccoli transplant date of July 28, back up another 5 weeks for indoor seeding and you get June 23. Yes, you start your fall broccoli in June. That's not a typo, and it's the number one reason people miss fall brassicas entirely.

The frost-tolerance adjustment. The formula above assumes first frost is a hard stop. It is for beans, squash, and cucumbers. It isn't for kale, spinach, carrots, leeks, or collards, which shrug off a 28°F night and often improve after one. For those crops you can push the sowing date 2 to 3 weeks later than the formula says, because they'll finish under a row cover or simply hold in the ground through November. Kale and carrots you planted for October are frequently still there in December.

If you'd rather see the whole month laid out crop by crop, we have dedicated guides for what to plant in September and what to plant in October.

The Master Vegetable Planting Schedule Table

This is the reference table the arithmetic feeds on. "Weeks before LF" means weeks before your last spring frost. "Fall window" is expressed as weeks before your first fall frost, which already includes the fall factor, so you can read it straight off.

Save this table and you never need another planting guide for vegetable gardens. Every date you'll ever want comes out of it plus your two frost dates.

Cool-Season vs Warm-Season Crops, and the Soil Temperature That Decides

The split between the two halves of that table isn't about air temperature. It's about soil temperature at seed depth, which is what actually triggers germination. Sowing beans into 55°F soil doesn't give you slow beans, it gives you rotted beans.

A cheap probe thermometer pushed 2 inches into the bed at 9 a.m. tells you more than any calendar. Oregon State University Extension publishes the standard germination table that these figures follow.

The practical takeaway: cool-season crops are limited by heat at the back end, warm-season crops by cold at the front end. That's why lettuce bolts in July and why waiting one extra week to sow beans usually produces an earlier harvest than sowing into cold mud.

Succession Planting: The Part Most Calendars Skip

A single sowing date gives you one harvest. Succession sowing, planting the same crop at a fixed interval, gives you a steady supply and turns 30 pounds of ripe lettuce in one week into two heads a week for three months.

The interval isn't arbitrary. It's roughly the length of time a planting stays at eating quality.

Two plantings of cucumbers instead of one is the single highest-value change most gardeners can make to their veg growing calendar. The first planting carries July, then powdery mildew takes it, and the second planting is just starting to produce.

A Flower Planting Schedule Works the Same Way

Flowers use identical arithmetic, with one extra category: bulbs, which are scheduled off first frost rather than last.

A calendar for planting flowers built this way gives you continuous bloom rather than one glorious June and nothing after. Succession-sow zinnias and sunflowers every 2 to 3 weeks through early July and you'll be cutting into October.

Regional Calendars: Where the Standard Rhythm Breaks

Everything above assumes a single growing season bracketed by winter. In roughly the southern third of the country, that's the wrong shape entirely.

Texas, Florida, the Gulf Coast, low-desert Arizona, and southern California run two growing seasons with a summer gap instead of a winter one. Their limiting factor isn't frost, it's August. Tomatoes stop setting fruit above about 90°F daytime and 75°F nighttime, lettuce bolts, and brassicas simply refuse.

The practical rhythm there:

• Spring season: plant warm-season crops in February or March, harvest through June.
• Summer dead zone: July and August. Grow okra, southern peas, sweet potatoes, and Malabar spinach, or solarize the beds and rest.
• Fall season: replant warm-season crops in late July or August for an October harvest, then follow with cool-season crops.
• Winter: in zones 9 and 10, winter is the cool-season vegetable season. Lettuce, broccoli, carrots, and onions grow October through March.

Texas A&M AgriLife Extension and the University of Florida IFAS Extension both publish region-specific planting guides that reflect this two-season pattern, and they're worth more than any national chart if you garden there.

Two other regional cases worth naming. Pacific Northwest gardens west of the Cascades have long, cool, wet seasons: frost dates are generous, but soil warms late, so warm-season crops lag behind what the frost date suggests. High-elevation Mountain West gardens can have a 60-day frost-free window with frost possible in any month, so nearly everything is transplanted, and season extension isn't optional.

Putting Your Own Calendar Together in 20 Minutes

1. Look up both frost dates for your zip code and write them at the top of a page.
2. List the crops you actually eat. Not the ones in the catalog. Twelve is plenty.
3. Pull the DTM off each packet and note whether it counts from sowing or transplanting.
4. Run the spring formula for each: indoor start, then outdoor date.
5. Run the fall formula for each: first frost minus DTM minus 14 days.
6. Add succession intervals to the quick crops.
7. Put the indoor-start dates in your phone calendar with alerts. This is the step that makes it real. The February pepper date is the one people miss.
8. Write down what actually happened. Last frost is an average, and your yard has its own microclimate. After two seasons of notes, your calendar beats any published one.

Some gardeners layer moon phase on top of these dates. If that's you, our guide to planting by the moon explains how the traditional system works alongside the frost-date math rather than instead of it.

FAQ

What is a planting calendar and why does it need my zone?

A planting calendar is a list of dates telling you when to start, transplant, and sow each crop where you live. It needs your location because every date is calculated from your local frost dates, and those vary by two months or more across the US. A calendar built for Georgia will kill seedlings in Minnesota.

How do I find my last and first frost dates?

NOAA's National Centers for Environmental Information publishes freeze and frost date normals by weather station, and nearly every land-grant university extension service republishes them by county. Enter your zip code into our planting calendar and it pulls the nearest station's dates for you.

Does my USDA hardiness zone tell me when to plant?

No, and this is the most common misunderstanding in gardening. Hardiness zones are based on average annual extreme minimum winter temperature, so they tell you what perennials survive your winter. They don't tell you when spring frost ends. Use frost dates for timing and zones for plant selection.

How accurate are average frost dates?

They're a 50 percent probability, not a guarantee. Half the time your last frost comes later than the average date. If you're planting something you can't replace, wait 7 to 10 days past the average, or plant on schedule and keep row cover ready.

What's the difference between a spring calendar and a fall planting chart?

Spring dates count forward and backward from your last frost. Fall dates count backward from your first frost using days to maturity plus about 14 extra days, because shortening days and cooling soil slow growth in September. That fall factor is why a fall planting chart isn't just the spring one reversed.

Can I plant vegetables after my first fall frost?

Yes, for the hardy ones. Garlic goes in around first frost by design, spinach and mache can be sown for overwintering, and kale, leeks, and carrots already in the ground keep improving through hard freezes. Frost-tender crops are finished.

When should I start a flower planting schedule?

Work backward the same way: hardy annuals like sweet peas and larkspur start indoors 8 to 10 weeks before last frost, tender annuals like zinnias 4 to 6 weeks before. Spring-flowering bulbs are the exception and go in 4 to 6 weeks before your first fall frost so they get their required cold period.

What's the biggest mistake people make with a vegetable planting schedule?

Reading days to maturity from the wrong starting point. If a tomato packet says 75 days, that's 75 days from transplant, not from seed, so the real span from sowing to first ripe fruit is closer to 120 days. Get that wrong and every date downstream is wrong too.