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When to Plant Celery in Loudoun County, VA

Loudoun County, Virginia Zone 7a May

May in Loudoun County, Virginia — your action list

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

Avg. last frost April 18
Avg. first frost October 19
Soil temp (4") 66°F
Watering Moderate
Pest pressure Moderate
Daylight 14.1 hrs
  1. Start celery under lights

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

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Celery is a marshland plant that requires consistent moisture and cool temperatures to produce crisp, flavorful stalks. It is a rewarding but demanding garden crop.

Loudoun County, Virginia is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 19, giving you a growing season of approximately 184 days.

At an elevation of 857 feet, Loudoun County receives approximately 45.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Celery during the growing season.

Loudoun County, VA (Zone 7a) Moderate season
184 days
Last Spring Frost April 18
184 growing days
First Fall Frost October 19
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Loudoun County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jul 6 – Aug 31
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jul 11 – Sep 5
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 2 – Sep 27

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 Loudoun County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Celery prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Celery.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Celery.

How to Plant Celery

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

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

Succession Planting Celery

2
successive plantings in your 184-day season

Sow every 9.1 weeks. Last sowing by Jun 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Celery

Celery needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan 3.5" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4" 0" ❄️ Dormant
Apr 5.6" 4" 1.6" 💧 Light watering
May 5.6" 3.2" 2.4" 💧 Light watering
Jun 5.6" 4.7" 0.9" 💧 Light watering
Jul 5.6" 4.4" 1.2" 💧 Light watering
Aug 5.6" 4.6" 1" 💧 Light watering
Sep 5.6" 3.3" 2.3" 💧 Light watering
Oct 5.6" 3.4" 2.2" 💧 Light watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Loudoun County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Celery 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.

Celery needs ~2,050 GDD — county provides 3,772 GDD Excellent fit

Celery Planting Timeline — Loudoun County, VA

Celery Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest July 11 Jul 11 – Sep 5
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

184 days in Loudoun County

Growing Tips for Celery in Loudoun County

Direct sow Celery outdoors after April 18 in Loudoun County when soil has warmed and frost danger has passed.

Common pests for Celery 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. Keep soil consistently moist and never let it dry out. Blanch stalks by mounding soil or using collars for milder 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 Celery in Loudoun County, VA?

Loudoun County is in Zone 7a with an average last frost of April 18. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Loudoun County, VA?

Loudoun County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 19.

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Your Loudoun County Garden Planner — Free

A 24-page printable planner built for Loudoun County (Zone 7a). 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 Loudoun County, VA. 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.