California Planting Calendar: When to Sow and Plant, Frost Dates Included

Los Angeles tomatoes rarely die from cold. Growers who mark a last-frost date on the calendar and count forward from it are working from a number that doesn’t exist here — three decades of daily records show zero freezing days, no last frost, no first frost, nothing to count from at all. What actually kills the plant is a July heat spike or an irrigation line that gets cut off in August. Count from the wrong threat and you’ll water when you should be shading, or wait for a cold snap that summer will never send.

The frost window in California

At Los Angeles, the reference station NOAA uses for coastal Southern California, the 1991-2020 climate normals report no computable freeze date at all. NOAA’s National Centers for Environmental Information code that reading as “-666,” meaning three decades of daily records never produced a hard freeze to average. NOAA’s RCC ACIS daily archive confirms it directly: zero days at or below 32°F in 30 years, which adds up to a 365-day frost-free season in an average year.

What “frost-free” actually changes

A calendar built around frost dates does not really apply at the coast and through most of Southern California. There is no last spring frost to count forward from and no first fall frost to count backward from, because in a typical year neither one happens. The limits on what you can grow and when come instead from heat, drought, and water availability. A tomato plant in Los Angeles is far more likely to be stopped by a July heat spike or a cut-off irrigation schedule than by cold, which is why knowing What to Plant in California in February — while the soil is still cool and the frost-free season stretches out ahead — helps you start early, knowing What to Plant in California in March — before the heat builds and while cool-season crops still have room to grow — sets the stage for the rest of the year, knowing What to Plant in California in April — while soil is still cool and water demand is low — matters more than tracking a frost date that never arrives, knowing What to Plant in California in May — as the days lengthen and warmth becomes reliable — keeps the momentum going, knowing What to Plant in California in June helps you get ahead of the heat before it peaks, understanding What to Plant in California in July matters just as much once the heat sets in, staying on top of What to Plant in California in August keeps you ahead of the season’s peak stress, tracking What to Plant in California in September helps you catch the first easing of heat as summer winds down, and knowing What to Plant in California in November keeps the cool season moving once that heat finally breaks.

That pattern does not hold everywhere in the state, and even where it does, the cool season carries on through year’s end, with knowing What to Plant in California in October helping you ease into that transition as summer heat starts to fade, with knowing What to Plant in California in January keeping the momentum going once the new year begins — knowing What to Plant in California in December keeps that momentum going as the year closes. Northern California, the Central Valley, and the Sierra Nevada foothills and higher elevations all see real freezes, some of them hard and long-lasting at altitude. Exact last and first frost dates for those regions are not part of the Los Angeles record above, and they shift quickly with elevation and distance from the coast, so confirm your own county’s figures through your local Cooperative Extension office rather than borrowing a coastal date. A grower working a Sierra foothill garden plans closer to the way growers do in Colorado’s mountain valleys or on Alberta’s short prairie season than to a frost-free Los Angeles yard, even though all three fall under one state-wide guide. For how these regional differences play out crop by crop, our California guides break the state down further.

Cool-season crops

Peas, spinach, lettuce, the brassicas (broccoli, cabbage, kale, Brussels sprouts), and root crops like carrots, beets, and radishes all tolerate cold better than heat. Where a real frost season exists, that is why they go into the ground before the last frost rather than after it: a light freeze rarely bothers a pea seedling or a young spinach plant, but a run of hot days will send lettuce straight to bolting and turn spinach bitter.

Timing by frost, or by heat, depending on where you garden

At the coast and through Southern California, where NOAA’s data shows no last frost to count from, the calendar for these crops flips. Instead of racing to beat the cold, you are racing to get a harvest in before the season’s heat arrives, so peas, spinach, and lettuce go in during the cooler months of the year and brassica transplants are expected to head up before daytime temperatures climb, rather than being timed off a frost date that never comes.

Inland and at elevation, where freezes do occur, the more familiar frost-based order applies. Peas and spinach seed generally go in the ground well ahead of the last frost. Brassica transplants and root crop seed usually wait until closer to it, and tender lettuce transplants are safest set out right around the last frost date rather than well before. Because that date is not fixed for the whole state, confirm it for your county through your local UC Cooperative Extension office rather than relying on a single statewide figure.

• Peas: direct-seeded, tolerates a light frost, sown well ahead of the last frost inland
• Spinach: direct-seeded, cold-hardy, bolts fast once heat arrives
• Lettuce: transplants safest right around the last frost date where frost occurs
• Brassicas: broccoli, cabbage, kale, Brussels sprouts, transplanted a few weeks before to a few weeks after the last frost
• Root crops: carrots, beets, radishes, direct-seeded, tolerate cool soil well

Warm-season crops

Tomatoes, peppers, squash, beans, and corn need warm soil, not just an absence of frost. Even where NOAA’s data shows no freeze risk at all, as it does for Los Angeles, seed sown into cold soil germinates slowly or rots, and transplants set out too early just sit there instead of growing. Soil temperature, not the frost date, is what actually decides when it’s time to plant, and a simple probe thermometer pushed a few inches into the bed tells you more than the air temperature ever will.

Why the frost date alone is not enough

In a frost-prone part of the state, the standard advice is to wait until after the last frost to set out warm-season transplants. That still leaves you guessing at soil warmth, because a clear, calm night can drop air temperature toward freezing while the soil several inches down stays milder, and a run of cloudy, cool days can hold soil temperatures down well after the last frost has technically passed. In Los Angeles, where the frost date does not exist to wait for in the first place, soil warmth becomes the entire test. Hold off on tomatoes, peppers, squash, beans, and corn until the soil itself has warmed through, not just until the calendar says frost season is over.

Counting back for indoor starts

Tomato and pepper transplants are usually started indoors six to eight weeks before you plan to set them in the ground, a nursery-industry figure rather than a frost-based one, so count backward from your intended transplant date using that range instead of from any frost line. Once transplants go in, the catalog’s days-to-maturity figure tells you roughly how long you are waiting for the first ripe fruit, counted from that transplant date rather than from seed, and it typically varies by a week or two with the season’s own weather.

Those figures still let you compare varieties honestly. Sakura and Valentine are both listed at 55 days from transplant, so a plant set out at the start of your warm-season window should be close to first ripe fruit roughly eight weeks later. San Marzano II, at 78 days from transplant, needs closer to eleven weeks from that same start date, and Cherokee Purple and Big Beef Plus, both around 72 days, land in between.

Peppers, squash, beans, and corn follow the same soil-first logic even without specific cultivar figures listed here. Wait for warm soil, then count from your own seed packet’s days-to-maturity figure rather than from a frost date that, across much of coastal and Southern California, never really applies.

The fall planting window

Where the state does get a first fall frost, the standard method is to count backward from that date using a crop’s days-to-maturity figure, plus a margin of a couple of weeks for the slower growth that comes with shortening days and cooling soil in autumn. A crop listed at 60 days from seed or transplant often needs closer to 75 days worth of calendar time in fall, simply because growth slows as daylight drops.

What that looks like where there is no fall frost

NOAA’s records for Los Angeles show the same zero-freeze pattern in fall as in spring. No first fall frost occurs in an average year, so there is no date to count backward from at all. The fall planting window there is set by day length and easing heat, not by an approaching freeze. Cool-season crops such as spinach, lettuce, and brassicas go back into the ground as summer heat fades, essentially repeating the spring cool-season window in reverse, and can often keep producing right through the winter months since nothing arrives to kill them off.

In the Central Valley, the Sierra foothills, and Northern California, an actual first fall frost does show up, and it is worth working around rather than ignoring. Root crops like carrots and parsnips, along with kale and Brussels sprouts, are well known among gardeners for improving in flavor after a light frost, as cold triggers the plant to convert stored starches into sugars. Growers in those frost-affected regions can leave those crops in the ground through the season’s first light frosts on purpose and harvest afterward for better flavor, something a frost-free Los Angeles garden simply cannot do, since the trigger that sweetens them never arrives.

Reading a planting calendar properly

A state-wide planting calendar, including this one, is a starting point built from averages measured at a handful of reference stations, not a set of instructions for your specific yard. California’s geography makes that gap wider than in most states. A few miles of distance from the coast, a few hundred feet of elevation, or a low spot where cold air pools overnight can shift real frost risk well away from what a regional average predicts.

What actually varies from yard to yard

Coastal fog and the marine layer keep areas near the ocean, including Los Angeles, essentially frost-free by NOAA’s own record, but that same marine influence also keeps summers cooler there than a few miles inland, which can slow down heat-loving crops like tomatoes and peppers even in a technically frost-free zone. Urban heat from pavement, buildings, and south-facing walls can run a city garden noticeably warmer than an open field nearby, sometimes enough to matter for tender plants. And even in an area NOAA classifies as having zero measurable freeze days over 30 years, a rare, sharp cold snap can still occur and catch a garden off guard, because a 30-year average describes what usually happens, not what always will.

Rather than trusting a regional figure alone, watch your own garden. Keep a cheap soil thermometer on hand and check it before warm-season transplanting instead of guessing from the air temperature. Note the date of your own last and first frost, if you get one at all, for a few years running, since that personal record tells you more about your specific yard than any station average can. Ask neighbors with established gardens what actually happens on their property, particularly if you are in a low spot, near a slope, or somewhere the local topography might trap cold air.

Local help

For county-level last and first frost dates, soil testing, and planting timing specific to your own microclimate, contact your local office of the University of California Cooperative Extension (UC ANR). County offices can also connect you with local master gardener programs, which know the quirks of a specific valley, coastline, or foothill far better than a statewide average ever will. This is the fastest way to get an actual frost date for your address rather than the frost-free figures that apply near Los Angeles.

Common questions

Does California actually get frost?

Yes, but not everywhere. NOAA’s 1991-2020 climate normals show zero freeze days in an average year at Los Angeles, making coastal and Southern California essentially frost-free, but Northern California, the Central Valley, and the Sierra Nevada all see real freezes, some of them severe at higher elevations. Check your own county’s frost record through UC ANR rather than assuming either extreme applies to you.

Why do seed packets tell me to start tomatoes indoors so early if there’s no frost here?

That timing comes from how long it takes to grow a sturdy seedling, not from a frost date. Tomato and pepper seed is usually started six to eight weeks before you intend to transplant, and that count holds whether or not your area ever sees a freeze, because the plant still needs that time to develop before it goes in the ground.

Can I really garden year-round in Los Angeles?

In terms of frost, yes. NOAA’s data shows no freeze to stop you at any point in the year. In practice, summer heat, and in many years water restrictions, do more to limit what grows and when than the absence of frost ever will, so a year-round garden there still shifts crops with the seasons even without a freeze to force the change.

What USDA hardiness zone is California in?

There is no single zone for the whole state. California’s hardiness zones range widely with elevation and distance from the coast, from mild coastal and Southern California zones down to much colder ratings in the Sierra Nevada and northern mountains. Check the USDA hardiness map or your county UC ANR office for the zone at your specific address rather than relying on a statewide figure.

When should I plant a fall vegetable garden in California?

It depends on whether your area gets a first fall frost at all. Where it does, count backward from that date using the crop’s days-to-maturity figure plus extra time for slower autumn growth. Near the coast and through Southern California, where NOAA’s records show no fall frost in an average year, timing instead follows fading summer heat and shortening days rather than an approaching freeze.

Related guides

• Oregon Planting Calendar: When to Sow and Plant, Frost Dates Included
• Nevada Planting Calendar: When to Sow and Plant, Frost Dates Included
• Colorado Planting Calendar: When to Sow and Plant, Frost Dates Included