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When to Plant Celery in Johnson, VT

Celery
Lamoille County, Vermont Zone 5a July

July to-do list for Lamoille County, Vermont

Welcome to July in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 8
Avg. first frost October 6
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Start harvesting celery

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

  2. Direct-sow celery for cool weather

    Count back from your first frost (October 6) — these need to mature before the cold arrives.

Looking ahead to August
  • First harvests: celery

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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.

Johnson, Vermont is in USDA Zone 5a. The average last spring frost is May 8 and the first fall frost is October 6, giving you a growing season of approximately 151 days.

At an elevation of 823 feet, Lamoille County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Celery to ensure they mature before fall.

Johnson, VT (Zone 5a) Moderate season
151 days
Last Spring Frost May 8
151 growing days
First Fall Frost October 6

Johnson Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Celery Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jul 27 – Sep 21
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 25
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 19 Transplant: May 24 🍅 Harvest: Aug 16 – Oct 11

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 Johnson

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

Soil pH

Your soil pH (4.9–6.4) is more acidic than Celery prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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 151-day season

Sow every 9.1 weeks. Last sowing by Jun 08 to harvest before frost.

For a dedicated fall crop, sow by Jul 28.

Celery Water Budget

Plant needs
1.3″/week
Rainfall provides
1.3″/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 3.3" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.3" 0" ❄️ Dormant
May 5.6" 4.8" 0.8" 💧 Light watering
Jun 5.6" 4.3" 1.3" 💧 Light watering
Jul 5.6" 4.7" 0.9" 💧 Light watering
Aug 5.6" 3.9" 1.7" 💧 Light watering
Sep 5.6" 3.8" 1.8" 💧 Light watering
Oct 5.6" 3.9" 1.7" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Lamoille 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 ~1,225 GDD — county provides 1,849 GDD Excellent fit

Celery Planting Timeline — Johnson, VT

Celery Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 8 May 8 – May 22
Direct Sow April 24 Apr 24 – May 15
Harvest July 31 Jul 31 – Sep 25
Fall Sowing July 28 Jul 28 – Aug 11

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

Month-by-Month Timeline

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

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 5a

📆 Growing Season

151 days in Lamoille County

Growing Tips for Celery in Johnson

Direct sow Celery outdoors after May 08 in Lamoille 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 →

🌱

Your Lamoille County Garden Planner — Free

A 22-page printable planner built for Lamoille County (Zone 5a). 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 Lamoille County, VT. Local conditions may vary. Last updated: July 2026.