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When to Plant Celeriac in Sussex County, DE

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.

Sussex County, Delaware is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 7, giving you a growing season of approximately 218 days.

At an elevation of 1,090 feet, Sussex County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Celeriac during the growing season.

Sussex County, DE (Zone 7b) Long season
218 days
Last Spring Frost April 3
218 growing days
First Fall Frost November 7

Sussex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: Jul 10 – Aug 14
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: Jul 17 – Aug 21
Safe Start (90%) ✓ Fits season (70 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Aug 5 – Sep 9

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,191 gal / 100 sq ft
Celeriac needs ~1,760 GDD — county provides 3,488 GDD Excellent fit

Celeriac Planting Timeline โ€” Sussex County, DE

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
Fall Sowing August 29 Aug 29 โ€“ Sep 12
Harvest July 17 Jul 17 โ€“ Aug 21

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

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

100โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

218 days

Growing Tips for Sussex County

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

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Frequently Asked Questions

When should I plant Celeriac in Sussex County, DE?

Sussex County is in Zone 7b 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 Sussex County, DE?

Sussex County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is November 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sussex County gardeners in Zone 7b 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 Sussex County, DE. Local conditions may vary. Last updated: April 2026.