In Texas, turnips go in the ground in fall and again in late winter, never in midsummer. The only dated frost figures this page has come from Houston, the mild Gulf end of a state that spans USDA zones 6a to 10a. Treat them as one anchor point, not a statewide calendar, and count back from your own first freeze using Houston as the worked example.
The short answer for Texas
The Houston reference gives two frost bands to build a calendar around. According to NOAA’s 1991-2020 Climate Normals for the Houston Intercontinental station (IAH), the last spring 32°F freeze falls between February 4 and March 1. The first fall freeze falls between December 1 and December 19. Those dates are probabilities of a 32°F freeze, drawn from the 30 to 70 percent band. They do not say the freeze will arrive on that day. The first date in each pair is the early, riskier end of the band. The second is the later, safer one.
Turnips are a cool-season root, so the useful trick is to work backward from the fall band. Take the days to maturity printed on your seed packet, subtract them from December 1, and you have the latest sensible fall sowing date for a Houston-area garden. Sow earlier than that and the roots size up in cooling weather rather than in leftover heat. In late winter the logic runs the other way: sowing can begin around the February 4 to March 1 band, but the sooner you sow inside it, the more you are betting against a late freeze. Watch the ten-day forecast, not just the calendar.
One more number matters. The mean daily minimum of Houston’s coldest month is 43.7°F (NOAA NCEI Climate Normals 1991-2020). That is the average night low, not the record low, and it sits well above freezing. A winter crop in this part of the state is the normal way to grow turnips, not a gamble. For variety choices once you have a date, see The Best Turnips and Rutabaga for Texas. For the broader picture of the crop, start with Growing Turnips and Rutabaga in Texas.
What this page does not have: dated frost figures for the Panhandle, North Texas or the Hill Country. Rather than borrow Houston’s dates for those places, the sections below say what shifts and where to find the local numbers.
What will not work here
A Northern calendar fails first. Advice written for Minnesota says to sow as soon as the soil can be worked and harvest through summer. Apply that in Houston and spring roots meet heat before they bulk up. With the last freeze possibly as late as March 1, the spring window opens late and closes quickly. A roughly nine-month frost-free stretch sounds generous, but most of it is too warm for a tender turnip, and that is the real lesson of this territory. The problem is not a short season. It is the wrong kind of long one.
Rutabaga is the second casualty. It is the slower, longer-season cousin and wants an extended stretch of cool weather to finish. With the first fall freeze not arriving until December 1 to December 19 and winter nights averaging 43.7°F at the coldest, the Gulf coast gives you cool weather, but it does not give you a long, steady, cold run. A rutabaga sown too late is racing warming spring temperatures. If you want to try one, sow it at the early end of your fall window and expect uneven results.
Weekly watering is the third thing that does not hold up. Turnips need steady moisture to stay tender, and a root that swings between bone dry and soaked turns woody or splits. In the drier western half of the state, a single deep soak a week is rarely enough for shallow-rooted seedlings in warm weather. Even on the humid coast, a dry fall stretch can stall germination. Mulch lightly and check the top inch of soil every couple of days after sowing.
Humidity punishes the opposite mistake. Crowded rows hold moisture against the leaves, and in the humid Gulf that invites foliar disease. Thin seedlings to the spacing on the packet and give the rows airflow, even if the garden looks sparse at first. Dense stands also produce small roots, so crowding costs you twice.
Finally, do not plant turnips and call it done through a warm, late summer. Sowing in the heat gives poor germination and bitter, pungent roots. Wait for the fall window, even when the calendar feels late.
What changes across Texas
Texas is not one garden. The USDA Plant Hardiness Zone Map (2023 edition, based on 1991-2020 normals) places the state in zones 6a through 10a. That is a spread of four zones, built on a single variable: the average annual extreme minimum temperature. There is no single sowing answer for the whole state, and the Houston dates here cover only the mild end of that spread.
The further north or higher you go, the earlier the freeze bands move in fall and the later they release in spring. The Panhandle freezes months earlier in the fall and months later in spring than Houston does. Hill Country and North Texas sit between and differ again. A Panhandle gardener who adopted the Houston dates would be sowing into frozen ground in the spring or watching seedlings meet a hard freeze in the fall. Fall sowing there should move earlier, and the late-winter window narrows, so spring sowing generally slides later into a short cool stretch.
Even within Houston the numbers drift. The airport figures used here describe the IAH station, and Hobby airport runs about two weeks milder. A gardener near the bay may have a different first freeze than one near the northern edge of the metro area.
Hardiness zone is a poor tool for dating a sowing, because it records the winter extreme, not when frost arrives or leaves. Use the zone map to see where you sit in the range, and use the frost dates for the calendar. To find your own zone, check the USDA map by ZIP code rather than guessing from the state average.
Where to check this for your own county
Your state extension service is the next stop. In Texas that is Texas A&M AgriLife Extension, which has county offices across the state. A county recommendation beats a state one, and this page is the state one. It is built on a single reference station and cannot see your elevation, your soil or your microclimate.
Two things are worth looking for. First, the local planting calendar for your county or the nearest one, which lists vegetable sowing windows by region. Second, the varieties trialled in your county, since a turnip that performs in East Texas humidity may behave differently in the dry West. County agents and Master Gardener volunteers often know which varieties have done well locally, and they can answer questions about pests and soil that no statewide page can.
One caution on sources. The extension material this page was checked against does not include a Texas turnip sowing calendar, so it makes no claim to one. Look for the vegetable planting guide for your county, and if a guide is dated, check the year. Frost normals get updated every decade, and the 1991-2020 set used here is the current standard.
Checking this against your own garden
Your own observation outranks every date above. Three signals are easy to read without equipment.
- Soil warmth by feel. Push your hand a few inches into the bed in the morning. If it feels cool and slightly damp, it suits turnip germination. If it feels like bathwater, wait for fall, and if it is cold enough to ache, wait for a warmer week. A bed that warms early tells you that your garden runs ahead of the regional dates.
- The first flush of male flowers. Squash and cucumber vines in neighbors’ gardens produce male blooms first once spring warmth is established. When they appear, the spring turnip window is closing. In fall, the end of that flowering signals the heat is breaking.
- The first true leaves. After the seed leaves come the rough-edged true leaves. If they appear quickly and stay green, your timing suits the site. If seedlings stall, yellow or bolt, you sowed into the wrong temperature.
Write down what you see and when. After two seasons, your notes will describe your yard better than any state table.
Some gardeners also time this by the Moon: when to plant turnips by the moon, as almanac tradition rather than fact.
Common questions
Can I grow turnips in Texas all winter?
On the Gulf coast, largely yes. The coldest month averages a 43.7°F nightly minimum in Houston. Individual freezes still happen, so keep row cover handy. In the Panhandle and North Texas, hard freezes make winter harvesting far less reliable.
When is the last safe date to sow turnips in fall?
Count back from your first freeze using the days to maturity on the seed packet. For Houston, that first freeze falls between December 1 and December 19 on a 30 to 70 percent probability band. Other parts of Texas will differ, so use your county’s number.
Is spring or fall better for turnips in Texas?
Fall is the safer choice, because roots mature as the weather cools. Spring works if you sow early, but the window closes as heat builds, and in Houston a freeze is still possible up to March 1.
Do these dates apply to the whole state?
No. The Houston figures reflect the mild end of a state spanning USDA zones 6a to 10a. Even inside Houston, Hobby airport runs about two weeks milder than IAH, so a gardener on the coast side of town may sow later than one inland.