Nevada has no single planting date for unusual roots. The only dated frost figures this page can vouch for come from the Las Vegas airport, a desert urban-heat-island extreme, and they say little about Reno, Carson City or any garden at elevation. Sow by your own county’s frost dates, count back from the days to maturity on the seed packet, and treat this page as the statewide starting point.
The short answer for Nevada
No one calendar covers Nevada, and the numbers below show why. The dates in hand come from the Las Vegas airport weather station: the last spring freeze falls January 7 to February 1, and the first fall freeze December 8 to December 23. Those are the dates when the chance of a 32°F freeze sits in the 30% to 70% band, from NOAA’s 1991-2020 U.S. Climate Normals.
Read that carefully. These dates are a probability of a freeze, not a promise of one. A date inside the band means roughly even odds, not a guarantee that frost has ended or begun. Gardeners who plant on the first day of the band are betting on a coin flip, and the ones who wait for the far edge are betting on better odds.
They are also a floor, not a state average. Reno, Carson City and anywhere at elevation get frost months earlier in fall and months later in spring than the airport figures suggest. Do not sow in January because a Las Vegas table says so.
| Figure | Value | What it describes |
|---|---|---|
| Last spring freeze (30-70% band) | January 7 to February 1 | Las Vegas airport only |
| First fall freeze (30-70% band) | December 8 to December 23 | Las Vegas airport only |
| Coldest month, mean daily minimum | 39.6°F | Las Vegas reference station |
| Hardiness zone (USDA) | 4a-10a | The whole state |
What does carry across the state is the method. Find your local last spring frost and first fall frost, then work backward from the days to maturity printed on the packet. Hardy roots can usually go in as the soil becomes workable, while the slower ones need every week of warm season you can give them. A radish-type root and a long-season root such as salsify do not belong on the same date, even in the same bed.
For the wider picture of what grows here at all, see Growing Unusual Root Crops in Nevada.
What will not work here
Copying the Las Vegas dates into a northern garden fails first. Sow in late January in a frozen high-desert bed and the seed either rots or sits dormant until spring, long after the packet’s promised harvest date has passed. The airport’s 30-70% band is a desert-floor number. At elevation the same band falls months later in spring and months earlier in fall.
At the other end, the slowest roots lose in a short season. Parsnips, salsify and scorzonera are typically long-season crops that want a lot of days between sowing and harvest. If your first fall frost arrives months ahead of the Las Vegas figure, you may not have enough of those days, and a stunted, finger-thin root is the result. Pick faster types in the north and at altitude, and check the days to maturity before you buy.
Weekly watering is the next failure. Root seeds sown into hot, dry soil need the top inch to stay moist until they sprout, and a once-a-week soak leaves them baking in between. Seedlings that dry out, then get flooded, tend to fork or split. Uneven moisture shows up as woody, cracked roots, so a gardener who waters on a weekly schedule rather than by what the soil feels like will lose crops that a drip line would have saved.
Summer heat is the low desert’s real obstacle. With a coldest-month mean daily minimum of 39.6°F at the Las Vegas reference station, winter cold is not what stops a root crop there. Summer does. A spring sowing that matures into peak heat tends to bolt, turn bitter or go tough, and that is the mistake the mild-winter numbers invite. Fall sowing, timed ahead of that December freeze band, gives roots cooler growing weather.
One more trap hides in the hardiness zone. USDA zones are built on a single variable, the average annual extreme minimum temperature, so a zone number says whether a plant survives winter and nothing about whether it finishes before frost or tolerates July. Choosing varieties by zone alone is how people end up with a root that overwinters fine and never sizes up. The choices that hold up are covered in The Best Unusual Roots to Grow in Nevada.
What changes across Nevada
The USDA Plant Hardiness Zone Map (2023, based on 1991-2020 normals) puts Nevada anywhere from zone 4a to zone 10a. That is six full zone steps inside one state, which is a wider spread than many states get across their entire length. No single answer exists, and any page that gives one date for the whole state is guessing.
The map’s two ends describe different worlds. The 10a end is the warm southern desert floor, where winter is mild and summer is the problem. The 4a end is the cold, high country, where the question is whether the ground thaws in time and whether a fall freeze arrives before roots size up. The same packet of seed carries a different calendar at each end.
If you garden in the north or at altitude, shift three things. Move spring sowing later, to your own last frost rather than any published southern date. Pull your fall deadline earlier, because the first fall frost reaches you months ahead of the Las Vegas figure. And favor the quicker roots over the slowest ones, since your season has fewer days to spend.
Sheltered spots complicate this further. A south-facing wall, a raised bed or a low pocket where cold air settles can each shift your own frost dates by days or weeks from the town’s official numbers. Two neighbors a mile apart, one on a slope and one in the valley bottom, can plant a week or two apart and both be right.
To find your own zone, use the USDA Plant Hardiness Zone Map and look up your location there. This page will not tell you which zone you are in, because the map does that job better than any paragraph here.
Where to check this for your own county
Start with University of Nevada, Reno Extension, the state’s land-grant extension service. It is the official source for what works in Nevada gardens, and its staff work with the specific conditions of each county rather than the state as a whole.
Look for two things there. First, a local planting calendar for your county or nearest town, which gives frost dates and sowing windows for where you actually live. Second, the varieties that have been trialled in your county, because a root that thrived in a research plot at your elevation is a far safer buy than one that thrived somewhere with different heat and a different frost date.
A county recommendation beats a state one, every time. This page is the state one: it can tell you the shape of the problem, the spread of conditions and the method for finding your dates, but it cannot see your valley, your slope or your soil. It also does not have a Nevada county calendar to quote, so it does not make one up.
If the extension office has no calendar for unusual roots specifically, the vegetable calendars still help. Match your root to a familiar crop of similar hardiness, such as carrots for a cool-season root, and use that crop’s dates as your anchor. Then adjust by what you observe in your own beds.
Checking this against your own garden
Your own observation outranks every date on this page. A calendar is an average of many gardens, and yours is one garden. Three things worth watching cost nothing and need no instrument.
- Soil warmth by feel. Push your hand a few inches into the bed in the morning. If the soil feels cold and damp, seed will sit; if it feels neutral or warm, germination is likely. A bed that warms days before the one across the yard is a warm microclimate, and you can sow there first.
- First true leaves. After a seedling’s seed leaves come the first true leaves, and when they appear tells you how fast your site grows things. If sowings keep reaching that stage later than the packet suggests, your site runs cool or your soil is slow, and slower roots will struggle.
- Frost damage on tender plants. Note when frost last blackens a tender plant in spring and first does in fall. Over a season or two, that record becomes your own frost calendar, and it may differ from the nearest official station by weeks.
Keep a few lines in a notebook each year: sowing date, first true leaves, first frost nip. After two seasons you will have a calendar more accurate than anything published for the state.
Common questions
Can I use the Las Vegas frost dates anywhere in Nevada?
No. The January 7 to February 1 and December 8 to December 23 figures describe the Las Vegas airport, a desert urban-heat-island extreme. Reno, Carson City and higher ground get frost months earlier in fall and months later in spring, so use your own county’s dates.
Is zone 4a to 10a my zone?
That range covers the whole state, not any one garden. Look up your own location on the USDA Plant Hardiness Zone Map, and remember a zone reflects winter cold only, not summer heat or season length.
Should I sow in spring or fall?
It depends on where you garden. Where summer heat is the obstacle, as the Las Vegas figures suggest, fall sowing ahead of the first freeze gives roots cooler growing weather. In the north and at altitude, the short season pushes the other way, toward a spring sowing and faster-maturing roots.
What does the 39.6°F figure mean?
It is the mean daily minimum of the coldest month at the Las Vegas reference station, from the 1991-2020 normals. It is neither the record low nor the monthly average, so a cold snap can still dip well below it.