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When to Plant Celeriac in Harrison County, MS

Harrison County, Mississippi Zone 9a May

May to-do list for Harrison County, Mississippi

May is a pivotal month for Harrison County, Mississippi gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
A few tasks this May that'll pay off in June
  • First harvests: celeriac

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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.

Harrison County, Mississippi is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 190 feet, Harrison County receives approximately 53 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Celeriac may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Celeriac will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Celeriac root diseases.

Harrison County, MS (Zone 9a) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26
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Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Start indoors: Jan 21 Transplant: Feb 18 🍅 Harvest: Jun 3 – Jul 8
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: Jul 9 – Aug 13

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 Harrison County

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

Soil pH

Your soil pH (4.8–6.2) is more acidic than Celeriac prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Harrison County warms quickly in spring but drains fast. Celeriac will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Celeriac.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Celeriac.

How to Plant Celeriac

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 4.1" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 3.9" 4.9" 0" ✅ Rainfall sufficient
Apr 3.9" 3.8" 0.1" 💧 Light watering
May 3.9" 4.1" 0" ✅ Rainfall sufficient
Jun 3.9" 4.9" 0" ✅ Rainfall sufficient
Jul 3.9" 6.3" 0" ✅ Rainfall sufficient
Aug 3.9" 4.5" 0" ✅ Rainfall sufficient
Sep 3.9" 4.2" 0" ✅ Rainfall sufficient
Oct 3.9" 3.6" 0.3" 💧 Light watering
Nov 3.9" 4.3" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Harrison County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~2,420 GDD — county provides 5,874 GDD Excellent fit

Celeriac Planting Timeline — Harrison County, MS

Celeriac Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors March 4 Mar 4 – Mar 18
Direct Sow February 11 Feb 11 – Mar 4
Harvest June 17 Jun 17 – Jul 22
Fall Sowing October 1 Oct 1 – Oct 15

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

267 days in Harrison County

Growing Tips for Celeriac in Harrison County

Direct sow Celeriac outdoors after March 04 in Harrison County when soil has warmed and frost danger has passed.

Sandy soil in Harrison County dries quickly — mulch Celeriac with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Harrison 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 Harrison County, MS?

Harrison County is in Zone 9a with an average last frost of March 4. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, MS?

Harrison County, Mississippi is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 26.

🌱

Your Harrison County Garden Planner — Free

A 24-page printable planner built for Harrison County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Harrison County, MS. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.