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When to Plant Celeriac in Simpson County, MS

Celeriac is a celery relative grown for its knobby, flavorful root rather than its stalks. It has a rich celery flavor and is excellent roasted, mashed, or in soups.

Simpson County, Mississippi is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 15, giving you a growing season of approximately 250 days.

At an elevation of 90 feet, Simpson County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97ยฐF, so Celeriac may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Celeriac, but amend with compost to improve drainage and prevent root rot.

Simpson County, MS (Zone 8a) Long season
250 days
Last Spring Frost March 10
250 growing days
First Fall Frost November 15

Simpson County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Jan 27 Transplant: Mar 3 🍅 Harvest: Jun 16 – Jul 21
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: Jun 23 – Jul 28
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 23 Transplant: Mar 30 🍅 Harvest: Jul 13 – Aug 17

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Simpson County

How your county's soil matches Celeriac's growing requirements.

Soil pH

Your soil pH (5.6โ€“6.8) overlaps with Celeriac's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

Your soil has 32% clay, which can cause forked or stunted roots for Celeriac. Use raised beds with loose, sandy mix for best results.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Celeriac.

How to Plant Celeriac

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 232 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celeriac

Celeriac needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Celeriac Needs Rainfall You Supplement Action
Jan โ€” 4.3" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar 3.9" 4.3" 0" โœ… Rainfall sufficient
Apr 3.9" 3.9" 0" โœ… Rainfall sufficient
May 3.9" 4.1" 0" โœ… Rainfall sufficient
Jun 3.9" 4.9" 0" โœ… Rainfall sufficient
Jul 3.9" 4.8" 0" โœ… Rainfall sufficient
Aug 3.9" 4.1" 0" โœ… Rainfall sufficient
Sep 3.9" 3.9" 0" โœ… Rainfall sufficient
Oct 3.9" 2.9" 1" ๐Ÿ’ง Light watering
Nov 3.9" 3.4" 0.5" ๐Ÿ’ง Light watering
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Simpson County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Celeriac Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Celeriac needs ~2,502 GDD — county provides 5,687 GDD Excellent fit

Celeriac Planting Timeline โ€” Simpson County, MS

Celeriac Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 โ€“ Feb 17
Transplant Outdoors March 10 Mar 10 โ€“ Mar 24
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest June 23 Jun 23 โ€“ Jul 28
Fall Sowing September 6 Sep 6 โ€“ Sep 20

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May โ€”
June Harvest
July Harvest
August โ€”
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

100โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

250 days in Simpson County

Growing Tips for Celeriac in Simpson County

Direct sow Celeriac outdoors after March 10 in Simpson County when soil has warmed and frost danger has passed.

With Simpson County's clay soil (32% clay), work in 3-4 inches of compost before planting Celeriac. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97ยฐF in Simpson County, provide afternoon shade for Celeriac and water deeply in the morning.

Common pests for Celeriac in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Remove side roots as they develop to encourage a single large bulb. Harvest after a light frost for best flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celeriac in Simpson County, MS?

Simpson County is in Zone 8a with an average last frost of March 10. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Simpson County, MS?

Simpson County, Mississippi is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Simpson County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Simpson County, MS. Local conditions may vary. Last updated: April 2026.