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When to Plant Celeriac in Marshall County, KY

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.

Marshall County, Kentucky is in USDA Zone 6b. The average last spring frost is April 3 and the first fall frost is November 1, giving you a growing season of approximately 212 days.

At an elevation of 1,550 feet, Marshall County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Celeriac during the growing season.

Marshall County, KY (Zone 6b) Long season
212 days
Last Spring Frost April 3
212 growing days
First Fall Frost November 1

Marshall County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: Jul 8 – Aug 12
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: Jul 17 – Aug 21
Safe Start (90%) ✓ Fits season (72 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Aug 1 – Sep 5

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 Marshall County

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

Soil pH

Your soil pH (5.5โ€“7.1) overlaps with Celeriac's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Marshall County is excellent for Celeriac โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 122 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€” 3.6" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar โ€” 4" 0" โ„๏ธ Dormant
Apr 3.9" 2.9" 1" ๐Ÿ’ง Light watering
May 3.9" 3.2" 0.7" ๐Ÿ’ง Light watering
Jun 3.9" 3.6" 0.3" ๐Ÿ’ง Light watering
Jul 3.9" 5" 0" โœ… Rainfall sufficient
Aug 3.9" 4" 0" โœ… Rainfall sufficient
Sep 3.9" 3.5" 0.4" ๐Ÿ’ง Light watering
Oct 3.9" 2.8" 1.1" ๐Ÿ’ง Light watering
Nov 3.9" 3" 0.9" ๐Ÿ’ง Light watering
Dec โ€” 3.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Marshall 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 ~1,842 GDD — county provides 3,551 GDD Excellent fit

Celeriac Planting Timeline โ€” Marshall County, KY

Celeriac Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 โ€“ Mar 13
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Direct Sow March 20 Mar 20 โ€“ Apr 10
Harvest July 17 Jul 17 โ€“ Aug 21
Fall Sowing August 23 Aug 23 โ€“ Sep 6

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July Harvest
August Fall Sowing Harvest
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 6b

๐Ÿ“† Growing Season

212 days in Marshall County

Growing Tips for Celeriac in Marshall County

Direct sow Celeriac outdoors after April 03 in Marshall County when soil has warmed and frost danger has passed.

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 Marshall County, KY?

Marshall County is in Zone 6b with an average last frost of April 3. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marshall County, KY?

Marshall County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 3 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marshall County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Marshall County, KY. Local conditions may vary. Last updated: April 2026.