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

New Mexico’s frost dates are the whole ballgame: get them wrong and you’re either babying frozen tomato starts in April or watching a hard freeze take your peppers in October. The last spring frost sets your earliest transplant date, and the first fall frost sets how long your season really runs — but both shift by a week or two once you leave the Albuquerque valley for higher ground or the southern counties. So before you sow anything, pull your own last spring frost window for your elevation and county, not the statewide average, and build your calendar backward from that.

The frost window in New Mexico

Every planting decision in New Mexico starts with two dates: the last spring frost and the first fall frost. At Albuquerque, NOAA’s 1991-2020 climate normals put the last spring frost between March 31 and April 12, and the first fall frost between October 29 and November 9 — see What to Plant in New Mexico in October for how that fall frost date shapes your last-chance plantings, check out What to Plant in New Mexico in March for what you can get started before that last frost even arrives, see What to Plant in New Mexico in May for the transition month as that last frost date approaches and passes, check out What to Plant in New Mexico in June for the window right after your last frost passes, or see What to Plant in New Mexico in July for what to sow once the frost risk has fully passed. Those are 30-70% freeze-probability windows measured at the Albuquerque airport station, not a promise for every yard in the metro area, let alone the rest of the state.

Higher elevation changes everything. Northern New Mexico towns and mountain valleys sit well above Albuquerque’s roughly 5,300-foot elevation, and cold air pools in low spots and drains downhill on clear nights. Gardeners in those areas should expect their last frost to land later in spring and their first frost to arrive earlier in fall than the Albuquerque figures above, often by a week or two, sometimes more at real elevation. The lower Rio Grande valley and the state’s southern counties tend to run the other direction, with a longer frost-free stretch than the reference city sees.

Do the arithmetic on the season length itself and you get a range, not a single number. Counting from the latest likely spring frost (April 12) to the earliest likely fall frost (October 29) gives a conservative season of about 200 days. Stretch it to the earliest spring frost (March 31) and latest fall frost (November 9) and the season runs closer to 223 days. Call it roughly six and a half to seven and a half months of workable frost-free growing at Albuquerque, understanding that your own garden may run shorter or longer depending on where it sits.

Why the range matters more than a single date

A 30-70% probability band means frost is genuinely possible on either side of that window, not just theoretically. Treating March 31 as a guarantee is how gardeners lose a tray of pepper seedlings to a cold night in early April. Treat the whole window as live risk, and push your riskiest transplants toward the later end of it unless you’re prepared to cover plants on short notice.

Cool-season crops — see What to Plant in New Mexico in April for a month-specific breakdown

Peas, spinach, lettuce, brassica transplants and most root crops tolerate a light frost because their foliage and root tissue handle temperatures well below what would kill a tomato seedling. That tolerance means these crops don’t wait for the last frost date at all. They go in ahead of it, timed off the frost window rather than off a fixed calendar month.

Peas and spinach are usually direct-sown four to six weeks before the last spring frost, as soon as the soil can be worked rather than waterlogged. Run that arithmetic against Albuquerque’s NOAA-normal frost window of March 31 to April 12: four weeks before the earliest date lands around March 3, and six weeks before the latest date lands around March 1. Combine those two calculations and you get a workable sowing range of roughly late February to mid-March for Albuquerque gardens, earlier if your soil warms and dries quickly, later at elevation where the ground stays frozen or soggy longer.

Lettuce and other leafy greens follow the same logic but tolerate slightly less cold once they’ve germinated, so many gardeners start them two to three weeks after the peas go in, or hold seedlings under row cover if a hard freeze is forecast. Brassica transplants, meaning broccoli, cabbage and kale started indoors and set out as young plants, generally go into the ground two to four weeks before the last frost since transplants carry more root mass than a freshly germinated seed and handle a light freeze better.

Root crops like carrots, beets and radishes are almost always direct-sown, since their taproots don’t transplant well. Radishes are quick enough to sow in succession every couple of weeks through the cool part of spring, and again in early fall once summer heat breaks. Carrots and beets take longer and are usually sown once, timed to mature before the heat of early summer makes their roots woody and bitter.

• Peas and spinach: direct-sow roughly four to six weeks before the last spring frost
• Lettuce: sow two to three weeks after peas, or protect seedlings if frost threatens
• Brassica transplants: set out two to four weeks before the last frost
• Carrots, beets, radishes: direct-sow early, radishes again in succession through spring

Warm-season crops

Tomatoes, peppers, squash, beans and corn all die at freezing, so the last spring frost date sets the earliest possible transplant date. But soil temperature matters more than the frost date alone: cold, wet soil rots seed and stunts transplants even when the air itself never dips to freezing. Warm-season crops generally wait until soil has warmed well past the point where frost is merely gone, which in practice means a week or two of buffer after the last frost window closes.

For the tomato cultivars in our catalogue, that buffer works out to a transplant window of mid-April to late April at Albuquerque, calculated from the NOAA last-frost range of March 31 to April 12 plus that extra margin for soil warmth. Peppers, which are even more cold-sensitive than tomatoes, generally go out at the same time or slightly later. Squash, beans and corn can be direct-sown once soil has warmed, usually alongside or shortly after the tomato transplant window.

Counting back to a seed-starting date

Indoor seed starting works backward from the transplant window. Tomatoes need roughly six to eight weeks of growth indoors before they’re ready to go in the ground. Counting eight weeks back from the early end of the transplant window (mid-April) and six weeks back from the late end (late April) gives a seed-starting range of roughly mid-February to mid-March for Albuquerque gardens. Start earlier than that and plants get leggy and rootbound waiting for the ground to warm. Start later and you lose weeks of harvest at the other end of the season.

Days-to-maturity figures on a seed packet are counted from the transplant date, not the sowing date, which is why a “60-day” tomato doesn’t ripen 60 days after you plant the seed. Sakura and Edox both reach maturity in 55 days from transplant, so setting them out in the mid-April to late-April window puts first ripe fruit around mid-June, leaving roughly 131 days of margin before the Albuquerque fall frost window even opens. Slower cultivars need more of that margin. San Marzano II and Celebrity Plus, both at 78 days from transplant, ripen around mid-July and still carry about 108 days of cushion before frost risk returns, generally enough to keep producing through the rest of the season.

The fall planting window

Fall planting works backward from the first frost instead of forward from the last one. At Albuquerque, NOAA’s 1991-2020 normals put the first fall frost between October 29 and November 9, and everything you plant for a fall harvest needs to reach maturity, or at least a harvestable size, before that window opens.

Start with the crop’s days to maturity, then add a buffer, because plants slow down as day length shortens even when temperatures are still mild. A crop rated 55 days in the heat of June can easily take 65 to 70 days in September, since cooler soil and shorter daylight slow both germination and growth. Extension services commonly recommend adding one to two weeks onto the seed packet’s days-to-maturity figure for anything sown for a fall harvest.

Counting back for a fall tomato crop

If you want a second tomato harvest in fall, count backward from the Albuquerque frost window using a fast cultivar. Sun Gold reaches maturity in 57 days from transplant, and Sakura in 55. Subtracting 55 to 57 days from the fall frost window of October 29 to November 9 lands you in the first half of September, and adding the one-to-two-week fall buffer pushes the required transplant date back to roughly the last week of August through the first week of September. Miss that window and the fruit simply won’t ripen before the season closes.

Cool-season crops behave differently in fall: several of them actually improve with a touch of frost. Kale and Brussels sprouts convert starches to sugars after a light freeze, coming out sweeter than a summer-grown crop. Spinach and carrots left in the ground through a mild frost often taste better than what you pulled in June. Radishes and lettuce can go back in as soon as the worst of summer heat breaks, since they tolerate the season’s first light frosts without much damage.

Reading a planting calendar properly

A state-wide planting calendar, this one included, is a starting point built from one weather station’s history. It cannot know whether your yard sits in a frost pocket at the bottom of a slope, backs onto a south-facing wall that holds heat, or bakes under an urban heat island effect from surrounding pavement. Those factors can shift your actual frost dates by a week or two in either direction from the Albuquerque figures used here.

Elevation is the biggest single variable across New Mexico. A calendar that works for the Rio Grande valley near Albuquerque can be badly wrong for a mountain town a thousand feet higher, where the growing season compresses from both ends. The same principle holds across state lines. A gardener comparing notes with someone in the Oklahoma panhandle should expect a noticeably different frost calendar. Our Oklahoma Planting Calendar shows how much that state’s frost windows diverge from New Mexico’s, driven by different terrain and weather patterns entirely. The gap widens even further with New England. The Rhode Island Planting Calendar runs on a coastal, humid climate that has almost nothing in common with New Mexico’s high desert beyond the fact that both places still answer to a last frost date.

What to watch in your own garden

Rather than trusting a single printed date, watch your own conditions directly:

• Soil temperature at planting depth, checked with an inexpensive soil thermometer
• Local microclimate signs, such as which parts of your yard frost first and last in a mild cold snap
• The ten-day forecast in the weeks around your expected frost window, not just the calendar date
• How exposed your garden is to cold air drainage from nearby higher ground

A calendar built from decades of averages can still miss this year’s late cold snap. Keep row cover or old sheets on hand through the shoulder weeks on either side of your last frost date, since a single freak night can undo weeks of careful timing.

Local help

For county-level frost dates, soil testing, and a planting calendar that reflects your specific elevation and microclimate, contact New Mexico State University’s Cooperative Extension Service through aces.nmsu.edu. NMSU’s county extension offices are the closest thing New Mexico gardeners have to a locally verified frost date, and they can also test your soil rather than leaving you to guess at pH and nutrient levels. Browse our wider New Mexico guides for more on gardening across the state’s range of climates, from the high desert around Albuquerque to the cooler mountain valleys further north. Treat the extension service as your first call before you finalize planting dates for a new garden site.

Common questions

What happens if I plant tomatoes before the last frost date in New Mexico?

A hard freeze will kill tomato seedlings outright, and even a light frost can damage foliage badly enough to set the plant back for weeks. Row covers or cloches can buy a few degrees of protection on a marginal night, but they won’t save a plant through a real freeze, so it’s safer to wait until you’re solidly past your local frost window rather than gambling on the early end of Albuquerque’s NOAA range.

My seed packet says 60 days to maturity but my tomato took much longer, why?

Days-to-maturity is counted from the transplant date, not from when you sowed the seed indoors. It also assumes steady summer warmth, so a cool spring, a stretch of cloudy weather, or a fall planting where daylight is shortening can all push the real number well past what’s printed on the packet.

Does Albuquerque’s frost date apply to the rest of New Mexico?

No. The dates in this guide come from the Albuquerque airport weather station, and NOAA’s own normals are specific to that site. Higher-elevation towns and mountain valleys typically see later last-spring frosts and earlier first-fall frosts than Albuquerque, sometimes by two weeks or more, so treat this calendar as a reference point and check with your county extension office for a figure closer to your own garden.

I don’t know my exact county frost date, what should I do?

Start by contacting NMSU’s Cooperative Extension Service for your county, since they keep more localized climate records than a single airport station can provide. In the meantime, watch your own garden for two or three seasons and note when frost actually shows up on your thermometer, not just on the calendar.

Can I direct-sow tomatoes instead of starting them indoors?

You can, but New Mexico’s frost-free season usually isn’t long enough to make it practical for most cultivars. Direct-sowing adds several weeks to the timeline compared to setting out a transplant, which eats into the margin you need before the first fall frost, especially with a longer-season variety like the 78-day San Marzano II or Celebrity Plus.

Related guides

• Arizona Planting Calendar: When to Sow and Plant, Frost Dates Included
• Utah Planting Calendar: When to Sow and Plant, Frost Dates Included
• Oklahoma Planting Calendar: When to Sow and Plant, Frost Dates Included