Set tomatoes out in Jackson anywhere from March 6 to March 22, and everywhere else in Mississippi it depends on how far you sit from that city. The frost window is what decides your date, not the calendar page or the day the nursery starts selling transplants. Find your own county’s typical last frost before you pick a day, since a garden thirty or forty miles out can run a week or two behind Jackson, and a transplant set too early meets ground that’s still too cold to grow in even after the air has stopped freezing.
What this comes down to in Mississippi
The frost window at Jackson runs from March 6 to March 22, per NOAA’s 1991-2020 climate normals, and that’s the single figure every Mississippi tomato date works back from. Transplants go in after that window closes, not on a single date somewhere inside it, because a light frost can still land on the early end of the range in a cool year. Treat the whole window as your risk zone, not just its middle, and have some kind of frost cover ready for the first two or three weeks after transplants go in the ground.
Catalog days-to-maturity figures assume this is roughly when the clock starts. Nearly every cultivar sold for Mississippi’s season lists a mid-March to early-April transplant window, which lines up with the tail end of Jackson’s frost dates plus a short buffer for the soil to warm. Soil temperature, not the calendar, is what actually decides when it’s safe to transplant: cold, wet ground near the freeze line can stall or kill young plants even after the air itself has stopped freezing.
The other end of the season matters just as much. Jackson’s first fall frost falls between November 7 and November 22, also per NOAA’s normals, which gives a spring-set tomato crop somewhere close to seven and a half months before frost returns. The table below shows how that plays out for three cultivars at different ends of the season length, all set out in the same mid-March to early-April window:
| Variety | Days to maturity | First ripe fruit | Margin before Jackson’s first fall frost |
|---|---|---|---|
| Sun Gold | 57 days | Early June | 159 days |
| Cherokee Purple | 72 days | Mid June | 144 days |
| Amish Paste | 85 days | Late June | 131 days |
All three finish with well over four months to spare before Jackson’s frost returns, which is why days-to-maturity rarely rules out a spring planting here. That margin matters more for a second, fall-targeted planting than for the first one, which is where the math starts to get tight. For the full list of cultivars matched to this window and their disease resistance, see Tomato Varieties That Ripen in Time in Mississippi, and for the crop basics this page assumes, see growing tomatoes in Mississippi.
Working it out for your own garden
Start with the frost window itself and treat it as two ends of a rope, not a single point. Jackson’s last spring frost falls between March 6 and March 22, per NOAA’s 1991-2020 normals, and its first fall frost falls between November 7 and November 22. Subtracting the two gives a frost-free stretch of roughly seven and a half to eight and a half months, depending on where in each range a given year lands. Every days-to-maturity figure printed on a seed packet gets measured against that stretch, never against one calendar day.
The five steps
- Find your own county’s typical last spring frost from MSU Extension or the nearest NOAA station, not Jackson’s figure.
- Add a soil-warming buffer of a week or so if your ground is heavy clay, shaded, or slow to dry in spring.
- Check the cultivar’s days-to-maturity on the seed packet or catalog listing.
- Count that many days forward from your intended transplant date to estimate first ripe fruit.
- Compare that date against your county’s first fall frost to see how much margin you actually have.
Take Sun Gold as a worked example. It lists 57 days from transplant on the catalog tag. Count 57 days forward from an early-April transplant and first ripe fruit lands in early June, which matches the catalog figure. From there to the start of Jackson’s fall frost window in early November is roughly five months of harvest, leaving about 159 days of margin, far more than any Mississippi garden needs for a spring crop.
Now run the same math on a case that’s actually tight: not the spring planting, but a second, fall-targeted round. Amish Paste needs 85 days from transplant. Set a second batch out in early September hoping for a fall crop, and 85 days forward lands you at the tail end of November, past even the late end of Jackson’s fall frost window of November 7 to 22. That’s where the math stops working: a long-season paste tomato started that late has almost no cushion, and a single cool snap in early November can end the crop before it ripens. The fix isn’t a different variety, it’s an earlier succession date, worked out the same way but counted backward from your own county’s expected first frost rather than Jackson’s.
What changes across the state
Jackson sits in the middle of Mississippi’s tomato-growing range, and its frost dates aren’t the same as either end of the state. The USDA’s Plant Hardiness Zone Map lists the state’s zones as 7b to 9a, meaning the northern hill counties near the Tennessee line run noticeably cooler than the coastal counties near the Gulf. The general rule is south and low: the further south and closer to the coast a garden sits, the later the last spring frost tends to arrive and the later the first fall frost tends to hold off, stretching the usable season on both ends. Coastal counties often see their last frost end before Jackson’s window closes and their first fall frost arrive well after Jackson’s window opens. Northern counties tend to see the opposite: frost lingering later into spring and returning earlier in fall than at Jackson, tightening the season from both directions.
Elevation plays a smaller role in Mississippi than it does out west, since the state has little dramatic relief, but low-lying ground still collects cold air on clear nights regardless of latitude. A garden at the bottom of a slope, in a river bottom, or in an open field with no windbreak will read colder on a frost night than one on slightly higher, more sheltered ground even a few hundred yards away. That local cold-air drainage can shift your effective last frost by more than the county average suggests, which is one more reason the Jackson figures work as a reference point rather than an instruction.
None of this changes the underlying math, it just changes how much room it leaves. A shorter frost-free window in the north still gets checked against the same days-to-maturity numbers on the seed packet, it just leaves less margin on both ends, favoring shorter-season cultivars like Sun Gold or Sakura over an 85-day paste tomato for gardeners near the state’s northern edge.
The mistakes this state punishes
Mississippi throws out a stretch of warm days in February most years, often warm enough to fool a gardener into thinking the last frost has already passed. It hasn’t: Jackson’s own last frost window runs as late as March 22 in NOAA’s 1991-2020 normals, and a string of 70-degree days in late February says nothing about what a clear night in mid-March will do. Setting transplants out during a February warm spell is the single most common way Mississippi gardeners lose their first round of tomatoes, because there’s no frost cover ready when the cold snap that follows arrives.
The reverse mistake costs less fruit but more time. Since even a slow cultivar like Amish Paste, at 85 days, still leaves well over four months of margin before Jackson’s first fall frost, there’s little reason to delay a spring transplant past early April out of excess caution. Late transplanting mostly costs weeks of harvest, not the crop itself, because Mississippi’s frost-free stretch is long enough to absorb a delayed start for almost every cultivar sold here.
A third mistake is treating the whole state as one climate and copying a planting date from a forum post or a neighbor two counties over. A grower in the Delta and a grower on the coast are working with different frost windows even though both fall inside the same 7b to 9a hardiness range the USDA map assigns the state as a whole. Set your date from your own county’s figures, not someone else’s yard, and keep an eye on the pests that arrive once the weather warms, covered separately at Tomato Pests in Mississippi: Which Ones Actually Show Up Here.
Checking this against your county
The Jackson figures in this piece come from one NOAA weather station, and they’re a starting point, not an instruction for a garden forty or eighty miles away. Call your county’s MSU Extension office before you commit to a date, since Mississippi State University’s Extension Service keeps local frost records and planting guides that go beyond the single-station data NOAA publishes for Jackson.
If your garden sits in a low spot, near a large body of water, or well north or south of Jackson, ask the extension office specifically about local frost variation rather than relying on the statewide hardiness zone number alone. A five-minute phone call beats a guess when a single frost event can wipe out a whole flat of transplants.
Common questions
Can I plant tomatoes in Mississippi in February?
Not as a rule. Jackson’s last spring frost can run as late as March 22 in NOAA’s 1991-2020 normals, and February warm spells are common in Mississippi and don’t mean frost season is over. A February transplant usually needs full-time frost protection it won’t get.
What if I missed the mid-March to early-April window, is it too late?
Usually not. Most cultivars sold for this state leave more than four months of margin before Jackson’s fall frost even when set out on time, so a transplant date pushed into May still finishes well ahead of the first fall frost in most years. You’ll just get a later first harvest.
Should I start tomato seeds indoors or buy transplants in Mississippi?
Either works, and days-to-maturity figures on seed packets are counted from the transplant date either way, not from the seed. If you start your own, count backward from your planned outdoor transplant date, giving several weeks for germination and growth indoors before that date arrives.
How do I find my exact last frost date instead of Jackson’s?
Ask your county’s MSU Extension office, since they track local frost data that can differ from the single Jackson weather station NOAA’s normals are built on. NOAA also publishes normals for other stations around the state if your county has one nearby.