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When to plant Celery in Conejos County, CO

Plant Celery in Conejos County, when soil hits 50°F — usually May 26. Continue planting through June 16 for the spring crop. A second sowing from July 9 to July 23 extends the harvest into fall.

When to Plant Celery in Conejos County, CO

Celery
Conejos County, Colorado Zone 5a June

This month in Conejos County, Colorado

Your Conejos County, Colorado garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost June 9
Avg. first frost September 17
Soil temp (4") 46°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Harden off and plant celery

    Your last frost (June 9) has passed. These warm-season crops can handle outdoor soil now.

Coming up in July — start thinking about
  • Starting indoors: celery
  • Fall sowing: 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.

Conejos County, Colorado is in USDA Zone 5a. The average last spring frost is June 9 and the first fall frost is September 17, giving you a growing season of approximately 100 days.

At an elevation of 6,770 feet, Conejos County receives approximately 24.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Celery to ensure they mature before fall.

Conejos County, CO (Zone 5a) Short season
100 days
Last Spring Frost June 9
100 growing days
First Fall Frost September 17

Conejos County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Celery Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Aug 22 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Sep 1 – Oct 27
Safe Start (90%) ✗ May not fit
Start indoors: May 18 Transplant: Jun 22 🍅 Harvest: Sep 14 – Nov 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.

Soil Compatibility in Conejos County

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

Soil pH

Your soil pH (6.6–7.8) is more alkaline than Celery prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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.

Celery Water Budget

Plant needs
1.3″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 307 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 2.7" 0" ❄️ Dormant
Jun 5.6" 1.7" 3.9" 🚿 Regular watering
Jul 5.6" 1.8" 3.8" 🚿 Regular watering
Aug 5.6" 2.5" 3.1" 🚿 Regular watering
Sep 5.6" 2.1" 3.5" 🚿 Regular watering
Oct 2.3" 0" ❄️ Dormant
Nov 1.7" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Conejos 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 ~1,150 GDD — county provides 1,150 GDD Tight fit

Celery Planting Timeline — Conejos County, CO

Celery Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 – May 19
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow May 26 May 26 – Jun 16
Harvest September 1 Sep 1 – Oct 27
Fall Sowing July 9 Jul 9 – Jul 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

100 days in Conejos County

Growing Tips for Celery in Conejos County

Direct sow Celery outdoors after June 09 in Conejos County when soil has warmed and frost danger has passed.

Your 100.0-day growing season in Conejos County is tight for Celery (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Celery in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

Conejos County receives only 24" of rain annually. Celery needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Conejos County, CO?

Conejos County is in Zone 5a with an average last frost of June 9. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Conejos County, CO?

Conejos County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 9 and first fall frost is September 17.

When should I plant Celery in Conejos County, CO?

In Conejos County, CO, plant Celery after the last frost (around June 9) and before the first frost (around September 17). Best results when soil holds above 50°F.

What growing zone is Conejos County, CO for Celery?

Conejos County sits in USDA Zone 5a. Celery grows reliably in zones 2a through 10b, so it's a good fit here.

Can Celery grow in Conejos County's climate?

Yes — Celery grows well in Conejos County's temperate climate. Conejos County averages a 100-day frost-free season, with last frost around June 9 and first frost around September 17.

🌱

Your Conejos County Garden Planner — Free

A 22-page printable planner built for Conejos 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 Conejos County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.