Texas has no single sweet potato planting date, because the state runs from the Gulf Coast to the Panhandle. Slips go in after the last spring freeze, once the soil has warmed. On the mild Gulf end that means roughly mid-March into June. Farther north and at higher elevation, the window opens later and closes sooner. Start from your local frost odds, then let the soil have the final word.
The short answer for Texas
Near Houston, sweet potato slips can go into the ground from about mid-March into June. That range comes from the frost dates at Bush Intercontinental Airport, which sit at the mild Gulf end of the state. It works as a Houston calendar and cannot stand in for a Texas one.
What do the Houston frost dates actually measure?
NOAA’s 1991-2020 Climate Normals for the Houston airport station (IAH) put the last spring freeze between February 4 and March 1. Those dates are probabilities of a 32°F freeze. On February 4, the odds of another freeze that spring are still 70 percent. By March 1 they have dropped to 30 percent.
Fall runs the other way. The first freeze arrives between December 1 and December 19, with a 30 percent chance it has already happened by December 1 and a 70 percent chance by December 19. Between those spring and fall dates, the reference station has well over nine months without a freeze.
Sweet potatoes come from the tropics and stall in cold ground, so your planting date belongs after the last-freeze date. Give it about two weeks past March 1, check that the soil feels warm, and you land on the mid-March start. Hobby Airport on Houston’s south side runs about two weeks milder than IAH, so a garden near it can start a little earlier.
How late can you plant sweet potatoes on the Gulf Coast?
Sweet potatoes need roughly three to four months from transplanting to digging. Slips set out at the end of June still have about five months before the earliest first-freeze date of December 1. A July planting works with quicker varieties. August cuts it close.
Heat is on your side here. The reference station averages 102.4 days a year at 90°F or higher, which is the weather sweet potato vines grow fastest in. For the full growing picture, see Growing Sweet Potatoes in Texas.
What will not work here
Can you plant sweet potatoes in Texas in February?
Along the Gulf, a warm week in early February is the classic trap. The February 4 date still carries a 70 percent chance of another 32°F freeze, and even March 1 carries 30 percent. Slips set out in that stretch either get frosted or sit in cold, wet ground and make no growth.
The bigger mistake is carrying a Houston date to another part of the state. A mid-March planting that suits the Gulf lands before the last freeze in North Texas and well before it in the Panhandle, where spring freezes run months later and fall freezes arrive months earlier. A garden up there that copies Houston’s calendar plants into frost.
Does summer rain change how you water and space sweet potatoes?
It does. Houston gets about 14.6 inches of rain across June, July and August, out of 51.8 inches for the year. June brings 6.0 inches, July 3.77 and August 4.84. That is a wet summer, and it defeats two common habits.
The first is tight spacing. Vines crowded together hold damp air under the leaves after a summer downpour, which invites rot. The second is a fixed weekly watering schedule. July is the driest month and also hot, and the station reaches 90°F or more on 102.4 days a year, so a dry spell can arrive quickly after a wet one.
Soil decides the rest. Clay holds an inch of rain far longer than sand, so plant in raised beds where drainage is poor. Sand lets the same inch through within a day, so a sandy bed may need water every second day even in a wet summer. A single thunderstorm also tends to run off hard ground instead of soaking in. A rain gauge, or a straight-sided can set out in the garden, tells you what your plot actually received.
What changes across Texas
The USDA Plant Hardiness Zone Map (2023 edition, built on 1991-2020 normals) runs from zone 6a to 10a across Texas. That is a wide spread, and no single planting answer fits all of it. Houston sits at the warm Gulf end, while the high Panhandle sits at the cold one, with North Texas and the Hill Country between them and different again.
The zone rests on one number, the average annual extreme minimum temperature. It says how cold winters get and nothing about how hot July runs or how many weeks the growing season holds. Two gardens in the same zone can still have different sweet potato seasons. Look up your own zone on the USDA map by ZIP code instead of assuming it.
A reader in the north or at altitude should shift in three ways. Plant later, because the soil warms later and nights stay cool well into spring. Count backward from your own first fall freeze, since three to four months of growth has to fit before it. And lean toward quicker-maturing types, which The Best Sweet Potatoes to Grow in Texas sorts by season length. A cover laid over the bed ahead of planting warms cold ground faster.
Where to check this for your own county
Texas A&M AgriLife Extension has offices in the state’s counties, and that is the best next stop. Look for two things there. The first is the local planting calendar for sweet potatoes, which usually follows a county or regional frost pattern. The second is the list of varieties trialled in your county, because a type that sizes up well in the Gulf’s long season may fall short in a shorter one.
It also helps to ask which weather station the county uses for frost dates, since the nearest airport may sit hotter or colder than your yard. County agents also know local soils, from sandy East Texas ground to heavy blackland clay, and which pests show up in your area.
A county recommendation beats a state one, every time. Anything written for all of Texas, including the Houston dates above, is a starting frame. The county agent’s advice comes from the soil and weather your garden actually shares.
Checking this against your own garden
Your own observations outrank every date here. Three are worth watching, and none needs equipment.
- Soil warmth by feel. Push your hand a few inches into the bed on a morning after a mild night. Soil that feels cool or clammy is not ready. Soil that feels comfortably warm, like a car seat in the shade, is. A bed that passes this test two weeks before your neighbor’s has a warm microclimate, often from a south-facing wall or sandy soil.
- New growth on the slips. Healthy slips push fresh leaves soon after planting. If they sit with yellowing or purple-tinged leaves and no new growth, the ground or the nights are still too cold for your spot.
- The last frost in your low spots. Note when frost last whitens the lowest corner of your yard. Cold air pools there, so it frosts last, and the date can run a couple of weeks behind a slope or a spot near the house.
The same watching works in fall. A light freeze that blackens the vines does not kill the roots at once, but chilled roots store poorly, so cut the vines and dig soon after.
The Moon calendar is a separate, older custom: see when to plant sweet potatoes by the moon, written as tradition rather than fact.
Common questions
What is the last frost date for sweet potatoes in Houston?
NOAA’s 1991-2020 normals for the Houston airport station give a last spring freeze between February 4 and March 1. Sweet potatoes go in about two weeks after that, once the soil feels warm. Other parts of Texas have very different dates.
Can you plant sweet potatoes in Texas in July?
On the Gulf end, yes, with a quicker variety. The earliest first-freeze date is December 1, which leaves the warm season behind. Farther north, fall freezes arrive sooner, and a July planting is a gamble.
Do sweet potatoes need a lot of water in a Texas summer?
New slips need steady moisture for the first couple of weeks. After the vines cover the ground, they handle heat well, and watering depends on your soil. Clay holds rain for about a week and sand drains within a day, so a rain gauge helps you decide.
How long do sweet potatoes take to mature?
Roughly three to four months from transplanting slips, depending on the variety. Count that span from the day slips go in, then check it against your first fall freeze date.