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When to Plant Celeriac in Westmoreland County, PA

Westmoreland County, Pennsylvania Zone 6b May

Top priorities for Westmoreland County, Pennsylvania gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 23
Avg. first frost October 27
Soil temp (4") 63°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Time to start celeriac inside

    Label every cell. You will absolutely forget which is which otherwise.

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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.

Westmoreland County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 27, giving you a growing season of approximately 187 days.

At an elevation of 894 feet, Westmoreland County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Celeriac during the growing season.

Westmoreland County, PA (Zone 6b) Moderate season
187 days
Last Spring Frost April 23
187 growing days
First Fall Frost October 27

Westmoreland County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jul 27 – Aug 31
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Aug 6 – Sep 10
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Aug 18 – Sep 22

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 Westmoreland 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

The silt loam soil in Westmoreland County is excellent for Celeriac — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.4%). 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
0.0″/week
Watering frequency Only during dry spells
Season total 55 gal / 100 sq ft

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 2.3" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 3.9" 3.4" 0.5" 💧 Light watering
May 3.9" 3.5" 0.4" 💧 Light watering
Jun 3.9" 3.8" 0.1" 💧 Light watering
Jul 3.9" 4.3" 0" ✅ Rainfall sufficient
Aug 3.9" 3.8" 0.1" 💧 Light watering
Sep 3.9" 3.2" 0.7" 💧 Light watering
Oct 3.9" 3.2" 0.7" 💧 Light watering
Nov 3.1" 0" ❄️ Dormant
Dec 2.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Westmoreland 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 ~2,008 GDD — county provides 3,412 GDD Excellent fit

Celeriac Planting Timeline — Westmoreland County, PA

Celeriac Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest August 6 Aug 6 – Sep 10
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

187 days in Westmoreland County

Growing Tips for Celeriac in Westmoreland County

Direct sow Celeriac outdoors after April 23 in Westmoreland 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 Westmoreland County, PA?

Westmoreland County is in Zone 6b with an average last frost of April 23. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is Westmoreland County, PA?

Westmoreland County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 27.

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Your Westmoreland County Garden Planner — Free

A 24-page printable planner built for Westmoreland County (Zone 6b). 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 Westmoreland County, PA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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