Yes, with a calendar that differs from the seed packet. Mississippi’s frost dates leave room for celeriac, kohlrabi, turnips, rutabagas, horseradish and Jerusalem artichokes. Heat, humidity and soil temperature set the real terms, though. Below: when the ground is ready, how long the season runs, what summer does to roots, and which types fit. For the wider group, start with Celeriac, Kohlrabi, Horseradish and Jerusalem Artichokes.
When the soil is warm enough in Mississippi
At the Jackson reference station, NOAA’s 1991-2020 Climate Normals put the last spring 32 F freeze between March 6 and March 22 (the 30 to 70 percent probability band). Those are odds, not a promise. A freeze after the later date would break no rule of nature.
The date is also a stand-in. Roots never see the air temperature; they live in soil, and soil lags behind the air in spring. It reaches workable warmth after the frost risk ends, not alongside it. A bed that has seen its last freeze can still be cold and soggy a few inches down, which is where a turnip seed or a celeriac transplant actually sits.
The station caution matters here. The figures come from one airport weather station. Suburban and rural gardens typically see the last spring frost later, often by one to two weeks, and more at elevation. If your garden sits outside a city, treat March 6 to March 22 as the earliest reasonable starting point, then check your own county’s numbers with your extension office.
Let a soil thermometer settle the argument
A basic soil thermometer pushed a few inches into the bed and read in the morning tells you more than any printed date. The right soil temperature differs by crop, and this page has no local trial figures to quote, so take those targets from Mississippi State University Extension. The types do sort themselves, though. Turnips, rutabagas and kohlrabi are the hardy ones and go in first. Celeriac arrives as a transplant, and a cold spell can stress young plants. Horseradish and Jerusalem artichokes are planted as dormant pieces of root or tuber, so they wait for workable soil rather than for warmth.
Soil runs the other way in fall. Late-summer ground is still warm, which helps seed come up but means the first sowing of the season needs watering to hold moisture. The first fall freeze lands between November 7 and November 22 at the same station (same caution: rural beds often see it one to two weeks earlier).
How long the season lasts here
Both ends of the window come from the same NOAA normals. The last spring freeze falls between March 6 and March 22. The first fall freeze falls between November 7 and November 22. Pair the earliest dates and you get 246 days. Pair the latest and you get 245. Cross them (early spring with late fall, or late spring with early fall) and the span runs from 230 to 261 days. Call it roughly 230 to 260 days at the reference station.
Gardens away from the airport lose some of that. If the last freeze comes one to two weeks later and the first one arrives one to two weeks sooner, a rural bed can give up a few weeks overall. It is still a long season by national standards. That length is what decides how you plan.
A long window allows a second sowing. Turnips and kohlrabi do not need to be squeezed into a single spring planting: sow in spring, then sow again in late summer so the crop matures in cooler fall weather and finishes before the first fall freeze. Count backward from your local fall date using the maturity figure on the seed packet. This page will not invent one. The succession sowing guide on this site walks through the spacing of repeat sowings.
Season length also changes whether transplanting is worth the root check. Turnips, rutabagas and kohlrabi resent root disturbance, and a window this long means no head start is needed, so direct sowing is the sensible default. Celeriac is the exception. It is the longest crop of the group and is nearly always set out as a transplant, and in Mississippi the days are rarely the limit. Summer heat is, which is the subject of the next section.
Neighboring states run on different clocks. Growing Unusual Root Crops in South Carolina and Growing Unusual Root Crops in Virginia show how the same crops shift with a shorter or longer window.
Heat and water in Mississippi
The brief for this page called for a count of days above 90 F and a summer rainfall total. Neither figure is in the verified data, so neither appears here. A guess would be worse than a gap. What can be said without numbers: Mississippi summers are hot and humid, and humidity is what turns heat from an inconvenience into a disease problem. Warm, wet air favors rot and leaf disease, and heavy rain after a dry spell can split roots. Ask your extension office for the heat and rainfall record nearest your garden.
The practices follow from that. Mulch keeps soil temperature and moisture even. A raised or well-drained bed keeps water from sitting around roots. Drip or soaker watering at the base keeps leaves dry. A little afternoon shade over the root zone helps in July and August. For celeriac, summer heat is the real question, so aim for maturity in cooler autumn weather and check the extension for the timing that works locally.
What winter decides
The coldest month at Jackson has a mean daily minimum of 36.6 F (NOAA 1991-2020 normals). That is an average of overnight lows, not the record low, and individual nights still fall below freezing. USDA’s 2023 Plant Hardiness Zone Map, which is built on the average annual extreme minimum, places the state in 7b to 9a. That is a territory-wide range, so other parts of Mississippi differ from the reference city.
In practice, winters are mild enough that horseradish, Jerusalem artichokes and hardy turnips and rutabagas can usually stay in the ground under a layer of mulch and be dug as needed. Lifting for storage becomes a choice rather than a rescue.
Site Jerusalem artichokes first and think about growing them second. They are effectively permanent once planted: every fragment of tuber left in the ground regrows. It is the single most regretted planting in many vegetable gardens. Give them a bounded corner, a deep container sunk in the ground, or a spot where spreading does no harm, never the middle of a bed. They also store inulin instead of starch, and many people find them hard on the digestion. A small first portion is the sensible way to find out where you stand.
Horseradish spreads from root pieces too, though less aggressively. Preparation needs care. Grating a fresh root releases compounds that burn the eyes and airways, so work with ventilation and keep your face away from the bowl.
If you do lift and store anything, inspect each root. A soft patch, a weeping spot or a moldy crown ends the question; discard it. A root that looks sound is not thereby safe, and no storage duration is guaranteed here.
Which these root crops suit Mississippi
Reason from the territory’s facts. A long window favors types that can be sown twice. Heat favors types that tolerate airflow and shade at the root. Humidity makes disease resistance the first criterion when you read a seed catalog or a trial report. The table sorts the group by type.
| Type | What Mississippi’s conditions ask of it | What to look for locally |
|---|---|---|
| Turnip and rutabaga | Spring and fall sowings fit the window; humid air raises disease pressure | Disease resistance, fall performance |
| Kohlrabi | Same window; quick crop suits repeat sowing | Resistance to heat splitting and disease |
| Celeriac | Longest crop; summer heat is the obstacle | Trial results from hot summers, timing for autumn finish |
| Horseradish | Perennial; mild winters leave it in the ground | Clean planting stock, containment |
| Jerusalem artichoke | Permanent once planted; thrives in mild winters | Siting before anything else |
Turnip, rutabaga and kohlrabi are all brassicas. They share their pests and diseases with cabbage, kale and mustard, so a gardener who rotates them into a cabbage bed has rotated nothing. Follow the rotation page on this site and give them a bed that has been out of brassicas.
No cultivar is named here, and that is deliberate. This page has no verified Mississippi trial data, and a variety that thrives in another state’s heat and humidity can fail in yours. The varieties trialled in your own state are the only recommendation that means anything, so contact Mississippi State University Extension or your county office for what has been tested near you.
Common questions
When can I plant unusual root crops in Mississippi?
At the Jackson reference station, the last spring 32 F freeze falls between March 6 and March 22, a probability range and not a guarantee. Rural gardens usually see it one to two weeks later. Wait for workable soil and check it with a thermometer, not the calendar.
Can I leave Jerusalem artichokes and horseradish in the ground over winter?
In most of the state, yes. The coldest month at Jackson averages a daily minimum of 36.6 F, and the USDA zone range is 7b to 9a. Just remember Jerusalem artichokes regrow from any tuber piece left behind, so choose the spot with that in mind.
Does Mississippi heat rule out celeriac?
The season length does not; heat and humidity are the concern. Aim to have it mature in cooler weather and ask your extension office which local timing and types have been trialled.
Which varieties should I buy?
Take the list from Mississippi State University Extension. Varieties trialled locally account for the heat, humidity and disease pressure in your garden, and this page does not name any it cannot verify.